I understand your situation, in that I was very religious, long ago, very worried what was a sin or not, though not involved in sorority rituals (no way I could afford joining a sorority, but I wasn't interested anyway.) I would call myself back then as being "scrupulous". I knew I was scrupulous. OCD wasn't an acronym I knew then.
Do you have a religious counselor? I probably recommend you see one from your religion choice.
I am not religious now, but I remember my extreme worrying, similar to yours.