Can't get aroused since breakup

I have been experiencing a tremendous amount of self-doubt, depression, and anxiety lately, although I think that I have been feeling this in some way for years. I feel trapped and stuck and don’t really know what to do about it. Sometimes I come out of this feeling and feel fantastic and in charge, and then slip back into the negative thoughts for no apparent reason. I feel like I continuously make decisions that ultimately make me more unhappy, although I try to make decisions that will make me feel better.
One major area in my life that is causing unrest is the women situation. Last year I broke up with my girlfriend, who abused my trust several times. It was the first serious relationship I had been in, although it was a long distance one. The relationship is part of the reason why I transferred from a small private arts school to a large public university (and possibly why I chose to go to the liberal arts school in the first place). This change of schools has left me feeling that I have sold myself short and must work that much harder to compensate. After the breakup I was sort of lost, but decided to continue at the large university anyway. It was a tough transition. I continuously slept with my ex quite a few times throughout the year because it was comfortable and easy. On the occasions where I did manage to bring other girls back to my place I experienced erectile dysfunction. This has seriously eroded my sense of self-worth and confidence. It has happened quite a few times since then. Each time I felt worse about myself and now have trouble trying to pursue other girls in fear that it will occur again. This leads me to hook up with my ex more. Over the summer I had my doctor prescribe me Cialis. I took it when I went to a music festival with a girl I was hooking up with and her friends. That night even with Cialis I experienced ED. I began to question if I was gay or asexual or something. I know I am not, but the negative thoughts persist. This problem does not occur with my ex. I have no idea how to get past this issue and is causing an emotional spiral on top of my other issues. I now question getting back together with my ex because I feel like it will alleviate the ED stress out of the equation or that she is the one. However, I will always think to myself that I failed to move forward. This causes me to be stuck in limbo land.
I am stressed out by school. I am taking a very hard load, and actually sign up for classes that are more difficult than what is required of me. While I like to push myself, I fear that I am setting myself up for failure. I have always thought of being a doctor, and I fear that if I don’t get into med school I will have no direction in life. I decided not to go to a prestigious university that I was accepted to this past year where I would have been guaranteed a good job straight out of college. Again, I feel like I have made the choice to fail. I often feel emasculated and weak.
Up here I don’t feel as though I have any true friends. All of my friends are currently superficial feeling. I often get restless at my fraternity because I feel as though I am wasting my life around stupid people doing mindless things. Any time I find people to be true friends with I back out of the opportunity. If they are girls I am afraid to develop a friendship because I feel like I am being pushed to hook up with them, which worries me because of the ED issue. With guys, I get wierded out for the same reason, due to the imaginary fear that I am gay. This has held me back from enjoying life and new experiences. I have always been shy, and my experiences in high school made it that much worse. Because of that experience I feel that I am weird and that people don’t like me. I have a very hard time trusting people and opening up emotionally. When I am home, I find that I compare myself to my old friends, who seem to be doing much better and are happier than me. I feel that my depression makes them like me less and that I am even losing them. I am very lonely here.
I need help and advice. I feel like I am spiraling, I often see only more depression in the future. Sometimes I even feel as though I am going insane, or am in the early stages of schizophrenia. I have started reading about religion, mysticism, and psychedelic drugs as means of making myself feel better. I have read that these substances can alleviate anxiety and depression and have been drawn towards them but have yet to try. I am worried that they might push me over the edge and cause a total break with reality for me. I have started having really negative thoughts regarding consumerism and capitalism, preferring more earth conscious ideas. Since EDC I have been highly concerned about drug abuse in the dance culture and that American youth is sliding towards depravity. I often can’t tell whether these thoughts are legitimate concerns or paranoid delusions.
I don’t have any real hobbies, and can’t seem to find joy in any activities usually. Everything feels like a chore and I have to push myself to do almost anything. Since I don’t do anything for fun, I get down on myself for not doing anything, telling myself that I am lazy and unmotivated. There is almost nothing I really ever want to do but sleep and read and drink with friends. Every day seems to pass by without me ever really enjoying it. I am always uptight and can’t really let loose unless I’m really drunk. I drink way more than I probably should, at one party I had 16 shots but did not black out.
I am worried about my parents whose relationship seems to become more and more strained. They do not seem to get along at all. Every time I am home every member of the family is usually in separate rooms on separate screens. Everyone is caught up in their little busy world.
I often can’t make decisions because it seems like either decision will end up depressing me further, no choices seem like good ones.
I want to not feel this way anymore. I do not feel this way all of the time. Sometimes I feel on top of the world. This is just all of the things that stress me out at different times, and sometimes all at once. I know it is just a mindset that needs to change, but I don’t know how to do it. I feel like I am complaining about superficial problems, and feel even weirder that I have to see a therapist to deal with them, but I’m not sure what else to do. I tell myself I need to just "man up" and face the fear but the issue is something that I don't have conscious control over. Ideas?

Tell your girl that you feel shy in bed. Unless she's a total ***** then she should help you out with that and tell you it's OK to be the way you are. Because I feel fear is stopping you and if she helps you to feel that whatever reaction your body has is OK then...

Dude, this goes waaaaay beyond just a simple sexual issue. Therapy is a must. Anxiety, depression, self-esteem; all of that needs to be dealt with and you'll likely find that your arousal issue will work out with it.

I feel like this issue with girls had turned into a phobia or something and I don't know how to deal with it...

Really, therapy. It's okay, you've got a ton to work through.

And any woman you're with until you're able to work though your own internal struggles will just turn around and make it about her instead of providing any support.

I dint really know how to work out all my ****. I go to therapy but I don't really see the point of it. It doesn't Ebert really seem to change anything