It’s very difficult to give you advice because there could be so many reasons why he is acting this way. Maybe he’s not that into you, as you say. I don’t think that’s it though. Maybe he has some physical problem. He could be impotent, or else suffers from premature ejaculation and is afraid of not satisfying you. He might be gay and not be admitting it to you, or even to himself. He could have a sexually transmitted disease and is afraid that if he tells you, you’ll drop him like a hot potato. He could be married and feels guilty having sex with you. I could go on, but I think you get the picture.

Assuming you don’t want to waste a lot of time in a relationship that is destined to go nowhere, you have to have a serious talk with him. You have to get him to tell you why he doesn’t want to have sex with you and then go from there. If he’s gay, then you have to break up. If he has a disease, you have to decide whether or not you want to take the risk of catching it. Etc. etc. Each of these scenarios will require you to make a decision. And if he won’t talk, then I guess you have to tell him goodbye because you can’t wait for ever.