Reread the advice from Guitar - Then ask yourself if it broke wide open. After you say nope, move on back to your happy life.
I agree that PEP was unnecessary. That is a hard drug to take with a hefty list of side effects. You did not have any risk of HIV from your exposure. The only ways HIV is transmitted is through unprotected vaginal or anal sex or sharing IV drug needles. You had protected anal. The condom didn't break as you would absolutely know if that happened. They break wide open. It's very noticeable. I'd consider if discontinuing pep would be in your best interest. It was irresponsible for the doctor to give you pep for a non exposure. You had no risk.
Find a new doctor and your life will improve. This one doesn't care about you. He gave you PEP to get you out of his office. You need to see a therapist for anxiety, instead of taking a chemical drug as a placebo. You can't get hiv when you used a condom and the doctor knows that.
Did you tell the doctor you used a condom so he could discuss your situation?