How will this work?

So my best friend of ten years broke up with his GF of 7 years about 8 months ago. For the last 5 months we have been indulging in "extra curricular friend activities". I know he is in no way shape or form ready for a relationship. He lost his great love and is a mess because of it. He has been on a streak of bad luck recently, and is finding things quite hard to deal with. Ive been there for him throughout all this. Stood by his side, and helped him through. I had been celibate for almost 6 years. Like him i have no desire to get into a relationship. I just dont love him and he does not love me either. (well we do love eachother, just not in that way) The s*x is great, ive only been with 3 people voluntarily, and he is by far the best. We had a conversation when drunk, about how both of us thought we were taking advantage of the others emotional state, and decided that since we both felt the same, no liberties were being taken. We were both just getting what we wanted, and decided there was nothing wrong with that. I'm just worried that when we are done with this kick we wont be as good friends as before. So far we have been able to be normal around eachother, still the same sick, twisted and creepy sense of humour. I really never thought i would ever feel safe/comfortable enough to be with a guy, hence the 6 year long celibacy kick. But he is the person i am most comfortable with. I really hope we havent killed our friendship. He is the only person who can talk to me when im stuck in a depression because he understands it so well. And i understand his depression in the same way. Our depressions are quite different, different reasons, symptoms etc, but each of us gets the other so well that the differences mean nothing, we know what the other one is thinking. Alot of the people in our lives think we should be together, but they dont get it. He does not love me like that. And i dont love him like that. Our love is odd. Its unconditional, we loose touch but as soon as we are together again its like no time has passed at all. We are always the same together, except of course for now, when its different, and a little scary. I know i have brought him back from the brink of the void, and he has done the same for me on several occasions. We have saved eachother from ourselves so many times, stopped eachother from doing very stupid things, but will we be able to continue that when the physical side burns itself out? I'm so verry confused by all this. I dont understand, why me? Why do this with me? How can he stand to see me naked? i'm not pretty, i dont have a good body, and im very messed up in the head. Oh by the way my depression relate to a deep hatred for myself, in case anyone didnt catch that. Will all this kill our ten year friendship. I dont think i could stand not having him in my life, I think he feels the same, he is always saying so. I just dont know.