Ask him. Don't play the guessing game. Even if you somehow manage to come up with a good answer it's unbelievable selfish and cringey for him to leave you hanging like that.
I'll give him the benefit of the doubt: maybe he's not an asshole but he doesn't know what the hell he's doing. Help him make up his mind by asking direct, clear questions in the kindest possible way. Don't let him drag this any further.
Let him go, what if you keep on waiting and then at the end nothing happens. You'll just end up hurt.
Sounds like he wanted to let you down gently by not even bothering to acknowledge your confession. But as the person above me said, communication is key and you won't find out until you ask him directly
What exactly is he waiting for...? Someone better to come along? If you have known each other for three years and that is the best answer he can give you. I would say, reflect on your feelings: is he really everything for you and you want to wait, ok than go for that (and I*d settle in for a longish wait) or did you fantasize him to perfection and in reality he is just a normal guy, who might not be perfect and might not even be perfect for you... than tell him how you felt with that answer, to give a reason for the wait or even ask him to honestly reject you if he cannot see you two together, cause that will hurt a lot for a moment, but be much better in the long run.
Wait for him! One year is nothing. One of my friend Waited two years for a guy and now they are happy together and engaged and they will get married after 4 month!
I've been in love with a guy for three years now and recently I told him how I felt and he told me that he wanted to wait till next year before getting in a relationship. He didn't reject me but he didn't say he liked me back and I don't know if I should wait for him or let him go.