can't get over ex!! HELPP

omg so we broke up like 7 months ago and dropped all contact with each and all that. After we broke up I found a job and started working out more, dropped my negative friends and gain confidence, I got rid of everything from him and try my best not to think of him no more but I can't help it .... also why does my stomach still drop when I hear his name or found out he's with someone else ? I just wanna get over him so bad bc I'm doing so good in life rn this is the ONLY thing holding me back what can I do??