Let me analyze some of these things. The story is really educational (you can learn some good lessons from it).
1.
I thought in my mind "oh well another average girl" but I still thought about her, I still glanced at her during class.
The curiosity at first developed into a crush within a month
This reminds me a clever person with Greek origin who said that love is autosuggestion (self-suggestion). If you don't focus too much on someone or something, you probably can't develop deep love feelings.
2.
, She was very very kind, we talked sometimes in English class and we had some in common. She'd always volunteer to help teachers, and she wasn't promiscuous. She doesn't use makeup, she doesn't use tiktok, she doesn't post on instagram and she keeps to herself. I knew that was the kind of girl I've been looking for.
If all these are true (I mean, it's hard to believe there are still girls who're not influenced by all these phenomenons), she is a real treasure and I think it was natural for a male person with good values to like her a lot.
I ended up leaving her on delivered for 2 months because my anxiety got so bad I couldn't open her message, when I wanted to check that message snapchat deleted it for me due to leaving it on delievered for too long. I never found out what she sent, but she definitely thought I trolled her.
This is really the problem. It's a sort of mentalcel issue. So we should learn to be braver. The brave one is not the person who doesn't feel fear but the one who acts even when he or she is scared. Not every brave man/woman is a fearless one.
3.
I started moneymaxxing seriously with my father's investment accounts he let me use and I made lots and lots of money.
I wish I could have a father like this one too. It's so good to have a good initial capital and to moneymaxx!

I started doing pushups and exercises in my room while motivating myself that I'd eventually get her, I still remember those days. I gained alot of muscle within my first month, I went from 100lbs to 113lbs while still staying very lean and cut.
I also motivating myself in this way!

Of course, it's probably a cope but it's working very well for me -- when I work out and I am getting a bit tired and/or bored I'm starting to think how my efforts are going to eventually help me to make my oneitis (or at least some similar girl) to like me.

It's a very sweet motivation!
4.
Near the end of summer I weighed 136lbs and below 12% bodyfat, I also did mewing and my face developed very well, I was very confident and was rated average 6-7/10 online and in real life.
So, it was enough! If you're already gymmaxxed and people rate you online and offline (a.k.a. "irl") at least 6.5/10, you're already not an incel (if you're not mentalcel, disabledcel or something else). I don't understand how a person after this still will decide to use steroids (a.k.a. roids)!
Don't do this! Instead, like me, start practicing several sports and healthy diets, work hard and you'll get
natural muscle mass (not very huge like the steroidal ones but real ones and with
lot of practical strength).
5.
You can see how much of a beta male I was when I found out she got back with her bf, I wished her the best and hoped things go well for them, but in reality? I was crying my eyes out, I couldn't believe yesterday's good news was this. I used up 3 rolls of toilet paper in the span of 2 days my eyes were not once dry. Even in my sleep those text messages haunted me. After a whole summer's self improving I was still a betamale in the end
A wrong ideal (understanding) what an alpha male should be. Being alpha doesn't mean to be hostile, rude, antisocial, etc. Exactly being emotionally stable, showing generosity and acting sane (even when you want to cry) shows the alpha-selfcontrol and doesn't ruin your future chances.
You did it right! In this way she is not going to hate you; she is also not going to tell anybody that you're a bad, dangerous, etc. person! So, every time try to keep it civilized except when there is really no other choice. 6.
I will try and forget her, I'll start by hating her for what she's done to me, for destroying me.
If you think you'll have no chance in future with her (what if she later decides to give you a chance because you really till now behaved like a real man and didn't insult her?) then of course you may try to forget her but not with hate. Hate doesn't help, it increases the chances to not forget the one you hate (it reinforces the memories). The best way is to search for another one. Well, there are no many unicorns like her indeed (she is really something) but surely there are other girls with other good sides (more or less), at least there will be some more pretty than her and/or more educated than her and/or more clean than her... so after you fall in love again, you'll not think about her so painfully and you'll be able to start being with an objective attitude towards her.
You're already gymmaxxed, moneymaxxed, not so shy anymore (no one can count you as a truecel, you're even not a mentalcel if you dare to approach new girl), so avoid suicidal ideas, blackpill ideas and other harmful stuff and keep the good self-improvement on!