Hello floral: Thank you for bringing your concern here to PC. I see this is your first post. So... welcome to Psych Central.

From what you wrote, it doesn't sound to me as though you abused your cousin. It sounds as though what you & your cousin did were things you both wanted to do. You wrote that the two of you maintained a good relationship once what the two of you were doing was over. Plus you wrote that you thought she might be wanting to do it again & you didn't. That doesn't sound like abuse to me. I'm glad you've talked about this with your counselor. It's good to have someone with whom you can talk these sorts of things through... open the doors & windows & let the sunshine in, so to speak.

The one thing you mentioned that might have been handled better was where your cousin brought up what the two of you had done & you pretended not to know what she was talking about. In current parlance you "gaslighted" her. My personal, non-professional opinion would be that the better way of having handled that might have been to acknowledge what you clearly know to have been the case, perhaps offer an apology for any hurt it may have caused, & state firmly that you would not want to do it again (if it seemed as though that was something your cousin was interested in seeing happen.) Perhaps it might be worthwhile talking this through with your counselor if you haven't already.

One of the concerns here is, I think, the guilt you are feeling over what occurred between you & your cousin. So here's a link to an article, from Psych Central's archives, on the subject of coping with guilt. This article provides links to a number of additional articles on the subject:

Coping with Guilt | Psych Central

I hope you find PC to be of benefit.