Why am I going insane?

I (20M) was with a girl (20F) for six months. I really liked her at the start and enjoyed her company.

I wanted to get it right and take it slow so it wouldn’t be messed up.

Just in casual conversation said she was really against sex until marriage and wanted to wait until the right person which was totally cool.
Then one night at midnight she spent an hour and a half forcing me to go to the shops to get condoms to do it. I was really against it and was uncomfortable but she kept forcing again and again telling me to go and get them so I did and it was not enjoyable.

Then another time about two months later I was ending it with her
She said we had a “karmic bond” and that we shouldn’t fight the desire to have sex and by physical. She kept saying the more we fight it the harder it is to resist and I just got tired and gave in.

And then on top of that we were flying back from holiday and on the plane and airport she was being all lovely and kissing me and holding my hand

Then we get home and she just says nah we need to stop.

The only thing we did was by physical I actually hated it and she forced it on me every time and usually as a guy I love that but I just hated it and every time you said no she would get all upset and start huffing and puffing.

On top of that every time I would say no about literally anything she would get so angry at me. We would study in the solent zone in the lbirary and if she was annoyed about something she would huff and puff and sniff and do all that until I gave her attention.

Then one night like 1.5 months in she was having a breakdown.I spent two hours trying to confront her but had an exam the next day. She went home and I asked her flat mate and sister to check on her but she was so angry I didn’t go home with her that night and look after her (when I had an exam the next day) and she held that over my head constantly saying how bad I was for that. How angry her parents would be if they heard and that I didn’t go home with her that night.

Like was I wrong of what I don’t get it.