Advice on a difficult obsession?

Sorry that this is so long- About 2 years ago, I was going through a strange phase (which didn’t last very long at all) where I thought it would be good to get more experience with women as a 21 year old male. Although I’m saving sex for marriage, I wanted to go out and try to be more outgoing and see if I was missing anything. I ended up going to a bar and getting drunk.I kissed a woman, and later stuck one my hands down in her pant ( we were both sitting down so I couldn’t have got too far) and touched her bottom. About a year after, I started obsessing over the event and made myself sick thinking about how this may have effected this woman, calling myself a monster and terrible person.I still haven’t been able to tame this problem and still have troubles with repetitive thoughts about it which sometimes are extremely frustrating. I am not a bad person and I am not some sort of sexual predator or deviant. I just was going through a phase and was very akward I suppose. She didn’t do anything to show me she didn’t want me and had friends around so I assume she wasn’t frightened or anything (that and I had being talking to her and her friends for a while). I remember at one point I got up adn went inside and one of her friends ran into me and said ‘you are the one who stuck your tounge down my friend’s throat?’ I was thrown off I guess and just said ‘ no…’ and she shook her head yes. In my head I seem to think that she told me I should leave after that but I cannot be sure if this was real or implanted in my head afterwards when I was at my worst of depression. Please tell me what you think and what you think would help me along. There is no way to meet up with this woman again ( fyi she was at least my age (21 at the time) but likely older). So I cannot apologize to her in person reasonably, and it happened almost two years ago. One of my worst obsessions was posting a similar question to this on YA to make sure that other people didn’t view me as a monster as I did/do. It’s as if two voices are in my head- my normal and my obsessive one that cannot drop this. I am just so afraid that she may have been frightned or felt violated by me kissing her and putting my hand in her pant… I just feel absolutly terrible, and I honestly didn;t mean any harm by my actions. I think about it 24/7 and can never give myself a break.. I feel like I don’t deserve it I still do drink, and although I think that had to do with the problem of losing inhibitions, it was my motivation to see if I was missing anything in the whole’ go out to a bar and make out with people’ scene that most of my peers had experience that had driven me to do what I did. Drinking may appear to be the problem, but it was only a factor in what I did, not the complete issue. we were not making out -I moved in and started to kiss her- and I was the one who pulled away… I don’t know if she didn’t want to make a move or if I was a little distant afterwards or what- it was definatly at the least a little akward. I had talked to the woman , as I was sitting with her and her friends, but to what extent and about what I cannot be sure as it was so long ago and I had been drinking. I didn’t feel particularly guilty afterwards, a little embarassed but the next week but that was it- so I don’t think there was anything then to go on that she was terribly bothered by it, but I still feel liek I can’t allow myself to drop it I feel like it has a lot to do with the fact that I am almost scared of sex- when I took the chance I did that night I got carried away and didn’t think of the effects it might have on me. Right now I have seen a therapist and we have dealt with some of my issues with my repressed sexuality, but didn’t mention this because I got nervous