I think you shouldn’t let this one emotion overpower your life. It’s okay. We all do mistakes. Try to accept it and move on in life by focusing on yourself prioritising the other relationships you currently have in your life.

Firstly stop following him on social media, and move on in your life , it might infatuation only

See, we do not love or hate the thing/person itself, we love or hate the 'feeling' about that thing/person which is inside of us. Yaani problem ka solution tumhare andar hi milega. I think in your case, you have facing some kind of 'Blankness' after Covid, when he move on with his life. Now You should see all this as God's choice. "Mann ka ho to achha, Na ho to aur achha". Ham insaan ko tbhi tak pasand karte hain jab tak wo mila nhi hota, milta hai to wo cheez/feeling dheere dheere polluted hi hoti hai due to human nature and expectations. You have 2 options right now, first Just search another guy, who is trustable and give you time. Second, Just Prepare youself in a way that you don't need anyone to be happy.

Please give more suggestions, I am still stuck at this feeling and I have been blaming myself again and again ,please help