Lost all hope and don't know how to move forward ?

My ex gf of a 3.6-month living relationship broke up with me in July 2024. What I understand from this is that she has been planning for this for a long time. But it was a sudden bomb for me. 2-3 months post-breakup I was really in a mess and could not able to think straight. Then I started to work on myself, hit the gym, became more focused towards my studies, and started to make new friends. I was trying everything to change myself and become a better version of myself but deep down I was holding hope of getting together with her again. No matter how much I tried I was not able to get rid of this hope because this hope was the only thing that was pushing me to change myself for her. I love her so much that I can do anything for her.

After a breakup in July till August 20th we were talking back and forth. She had already blocked me right after a breakup but she used to respond to my missed calls.

After the 20th of August, I went into total no contact and started to work on myself in the hope that maybe she would miss me and try to reach out to me but this never happened. Now after almost 6 months post-breakup she hasn't reached out to me but I was still holding on to the hope. As we both go to the same college and it's our last year we cross paths a few times but we don't each other and looking at her I can see she doesn't even care about my presence. As I was in NC I didn't try to stalk her to try to find out what's she doing. But in the last few days, some batchmates of mine told me that she was with a new guy. I haven't seen it with my own eyes but as this information has been given by 2-3 people I know it's true and even my heart can feel that it's true. My heart got shattered and I don't know how to move forward now. I feel like everything I have done during the relationship and even after the breakup, was just a big waste. All the ex-coming-back theories available on the internet are just bogus the art of manifestation its just time waste, true love is nothing. The thought of someone else touching her made me puke last night. If anyone could help me then please guide me. And if something same has happened with you please share your story with me so that i can understand how i should move forward from this. i m M/23 and my ex F/23