How to process a break up?

Hello, this is my first time posting on Reddit.

Recently, my relationship of 8 years just ended, and I don't know what I am supposed to do or feel. For context, for the past few months, I've been struggling in my studies and under a lot of pressure from my family. As a result, my behavior has been very pessimistic and distant, a significant contrast to what I used to be. I do admit that I lashed out and said stuff I didn't mean to like. I don't care anymore; it will be better for her without me, etc. I tried to apologize, but she gave up on me. She said she's been trying to keep what we had for quite some time, and she can't hold on anymore.

I am socially awkward, so I don't have friends, and she's the only person I talk to. Frankly, I am lost and don't know what to do.