Ever Seen the movie Made of Honor? Well thats my situation....at least I think

So what does it mean when things are between the friends zone and something else?I am the ever loyal friend of a guy who has/had many meaningless flings and a few girlfriends.All of which I had become good friends with as well......usually to his working.Sometimes I couldn't figure out if it was to get them off his back so he could have free time or if he did that so as to make our time spent together stress free so jealousy wouldn't come into play from his girlfriends.In any case we have been each others shoulder to cry on and more.Once about a year into our friendship he initiated flirting and a bit of strong sexual hinting verbally.In response I asked him flat out in a letter(we were far from one another for a little while).He didn't respond by letter but the next time I saw him in person he replied with"I actually really like you but you have way too much going on in your life right now" (I assumed it was due to the fact that yes at that time I was going through a sticky break-up from a 10 yr relationship)Well time passed and in that time I became very close with his family and friends and to him and vice versa. He would continue to flirt and it became some kind of weird game between us bus still no action.At one point I felt like it had been a joke to him and when I asked him he told me no.Now what I havent mentioned here is the fact that for the most part Im pretty confident except for one thing that Ive really been working on....which is my weight.Now mind you he has on several occasions during conversations with others he stated that he doesnt really care too much about his girl being skinny,or any particular body type but his previous girlfriends have been pretty tiny except for one. Because of this I have always held back my true feelings.I have been really working on slimming down and its working very slowly.Just a month ago he randomly brought up that one conversation we had and before I he could even really say much more I got so nervous I cut him off and said "oh no....Im so over that don't even worry about it".....like an idiot.The only thing he said was"Remember that question you wrote to me in the letter?I didn't write back because I didn't know what say but....." Mind you immediately before these statements he apologized for ruining my date that night because I ended up helping him out and canceling on my date.He jokingly offered his "booty call" services to me and we both just laughed.
Since that night we've been texting,calling each other and hanging out twice as much.He went out of town and is coming back in a few days.I have no clue what to do next if anything at all.I care for him so much Im scared that if he rejects me like that he will feel uncomfortable w me,then again I think I am in love with him and I know Ive never felt this way about anyone I have ever met.What the heck do I do?And how do I do it?