Hello there Luna:)
From what I have understood from your summary is that your friend may be a little bit confused himself, he wants you all the time and leans on you in the time of trouble yet doesn’t think you would work out in a relationship? So my guess is he really is just confused and doesn’t know how to feel about the situation , but to be honest you should think of yourself a little bit more than you think of him and I suggest you move a little bit away from him and not be as close as you used to be , at least until you recover from your own pain of the rejection. By taking care of him and how he feels and stepping on your own heart you are just going to hurt yourself and it is not going to be easy for you to get over this at all. I would talk to him about it though and explain to him that you just need a little bit of time alone to sort things out in your mind. You can listen to him when he needs you but try not to over do it for your own sake, you need to be able to think of your feelings in this as well and watch out that you don’t set yourself up for another heartbreak .
Hope I helped!
Alpal