I'm sorry you're struggling so much. Honestly, I think you are being a bit hard on yourself. I know you don't want to hear this comment, but you are still young, and you have plenty of time to grow emotionally and to work on your emotional intelligence.
I know you said you'd already done therapy "in your head," but none of us are capable of totally understanding ourselves. I suggest you do find a counselor to get more insight into your issues.
Please talk to your professors about your problems. Maybe they will cut you some slack and all won't be lost.
It isn't easy being bipolar. I know, because I am, too. But that's the hand we have been dealt.
We just have to start where we are and go from there. I assume you learned from your experience with the young woman. I guess you know she was not healthy for you. As you work on your issues, you will likely be able to attract healthier woman. Seek friendship first.
As you go along, I suggest you post in other forums such as the interpersonal relationship one. Perhaps the folks there can help you to make decisions and to get out socially in a healthier way. We can also provide friendships here.
All is not lost. Okay?