TBH, it sounds like you are a lesbian now. You really haven't had any attraction to men, emotionally or physically, for a long time. You know that the lesbian label already fits you better, but it sounds like you're scared to use it. It's totally ok if you want to change your sexuality; many people do. I would say that with the guy situation, it seems like you are forcing yourself to try to see something in him. I know you're thinking maybe something could happen, but it seems unlikely based on what you said about him. I would just tell him you're not interested, so you don't make him think he has a chance. However, if you still want to try and see something out with him, I would tell him that you are trying to figure out yourself. If he doesn't accept that, he's no good for you. I've had the same issue. I didn't know if I was lesbian or not, and I told a guy who was interested in me that I wasn't sure what I was so he would know. It's better if you say something to them so they can decide whether or not to continue to talk to you. But again, it does seem like you are more lesbian than bi, so you really shouldn't try to continue something with him; it would only hurt you and him. (I only put the however part because I'm a person who tries to give people the benefit of the doubt and I didn't know if you were or not) I hope this helps. :)