Possible New Diagnosis

Hi everyone!
Just wanted to share my story with you in hopes that others might be able to relate or offer some insight.
I'm a 22 year old college student who recently began seeing a therapist because I was incredibly depressed. I had been dealing with episodes of depression for years, but I always felt that I could manage them until this last time. So the first two sessions, my therapist saw me basically at my worst. However, by the third session, I had completely flipped, or so he says. I was feeling much better, so he asked me numerous questions relating to how I was feeling and whether I felt like this before, ect. He believes that I have bipolar disorder, however he is not sure where I am on the spectrum as of right now. He wants to see me a few more times before he gives me a final diagnosis. He also mentioned that some of the previous episodes I had experienced seemed to have included delusional thoughts.
I just feel like I'm at a loss. I always knew that I had mood swings, but always attributed them to teenage hormones, crazy sleep schedules, and stress from doing too much, as did everyone else around me. None of this feels real to me because while it fits the puzzle, it doesn't (if that makes any sense). If you look at my life on paper, I seem to have it all together. I'm a great student with many extracurriculars and volunteering activities. I've always based my emotional well being on how well I performed in school, regardless of how I functioned alone or outside of school. I guess I'm having a hard time accepting that something might be wrong.

I also have a few questions that some of you may be able to answer/comment about:
1) For those of you who experience delusional thoughts, do you know that they're not real when you're experiencing them? I've been told by others that sometimes my ideas are out there and they can't possibly be true, but I've always felt that they had to be real. I always came up with reasons why and could explain it to anyone based on these reasons. However, I would eventually start to deviate from the absolute belief that they are real, but instead I would start to question them. Do they still seem plausible? Yes, sometimes. I usually reach a point where I think that all of my crazy ideas might not be as real as I thought, but it's hard to completely shake of the idea because it was so real and I had an explanation for everything.
2) My therapist said he's trying to figure out whether my elevated moods are hypomanic or manic. Is there a particular way to be able to tell? I know that mania is seen in bipolar I whereas hypomania is seen in bipolar II, but how does one define too expansive? Does it have to do with functionality?

I hope this wasn't too long of a read!
Thanks for reading! And it's nice to meet all of you!

When I am manic I believe my thoughts are real, but there's always a tiny part of me that knows they're impossible. When I come down i realize the thoughts were delusional. As for the difference between mania and hypomania, for me I can tell by energy. When I am hypomanic I have more energy but I still sleep relatively well. When I am manic I generally don't sleep as much and I also start getting the delusional thoughts, such as believing I have magical healing powers. I also act fairly normal when I am hypomanic but when I am manic I will start doing weird things like going for a walk at midnight or tapping my feet constantly.

For me, sometimes I can feel the delusions setting in and know that the thoughts are out there, but once they are full on, there's no going back - they are all too real. In the midst of them, they are just legitimate thoughts and feelings and nobody can tell me that they aren't real because they just feel real. Nothing but time (for me) or meds can change that.

As for hypo/mania, people w/ BPI still get hypo, we just also have manic episodes on top of that. It only takes one manic episode to dx BPI. As for telling the difference, I believe my diagnosis came from the fact that I get delusional when manic, not when depressed whereas people with BPII get psychotic when depressed, not when they go up and so far as I know they are more likely to diagnose somebody as BPI if they get psychotic while up as opposed to down (but I am not a doctor, so you should bring this up with your doctor). Also, hypo will leave you with more energy and needing less sleep for a while, but mania will really wreck your sleeping patterns and derail you for longer than hypomania. Hypo is all like, you're more energetic or agitated, but mania is all like, super energetic/agitated and/or angry.

Hypomania can be needing less sleep for a few days (I believe the DSM says 4 days or more) but mania will leave you running on little to no seep for at least a week or two, though many, many times longer than that. For example: when I was 23, I stayed up all night for months, surviving off of short power naps during the day because I thought if I went to sleep (at night), space aliens would kidnap me in my sleep. (Though this is not to say that hypo cannot last longer, certainly it can, it's just not as intense and so far as I know, in BPII, the depressions are more intense, longer and some/many times psychotic.)

Were your delusions when you were depressed or when you were feeling "better"?

I only experience them when I'm feeling better.

And thank you both for your comments. They're extremely helpful!