Your feelings of guilt and unhappiness are in no real relation to what happened. Ok, it may have been wrong, BUT you were drunk, AND we are all human and make mistakes we later regret. We can later think things over and ask for forgiveness (we Catholics have confession

) and be at peace with ourselves again. We can learn from our experiences.
Making a mistake doesn't mean we have to be unhappy for years afterward!
Do you still know the woman? Have you talked to her again? Maybe she wouldn't even remember.
I know OCD thoughts can be very intrusive and come up with more and more reasons why you should worry. That is typical.
The form of OCD where a person feels excessive guilt is called scrupulosity. You could look that up too.
Kathrin