Would like tips from some people on sexual recovery

Hi, I am now 21 years old and have experienced some unfortunate sexual dysfunction right after my first relationship. I have NEVER had sexual problems my entire life until I broke up with my GF and we ended up having sex after words and I knew she was talking to another guy and I lost my erection during sex. It has plagued me for the last 9 months and every time I masturbate it’s to reassure myself that I have no dysfunction (sometimes I’m successful, sometimes not). It’s created a lot of anxiety and fear of having sex again so I’ve been trying to stop masturbating since it just keeps the thoughts of failing in my head. I have OCD and think about it a lot and try to counter the thoughts with positive affirmations. Thanks for listening and I appreciate any tips, I just want my life back.