Please help: how long should I wait for a response & where do I go from here?

Long story short, my boyfriend of 9 months had wanted a "break" from the relationship a bit over a week ago. His reasoning was because he's stressed/busy right now & the fact he's not sure we'll work down the road. He said it was possible we would if our paths seem to cross. Unfortunately, I had been quite negative/depressive lately & that was my choice. I am not proud of it at all & want to show him I'm working on changing (for the better..for myself & others). So I know my negativity was dragging him down some & getting old. Anyway, I truly respected him wanting space. I did not cling or become a blubbering mess. I have not hunted him down, texted/called a lot etc. I tried to handle the situation as maturely as possible (I'm 23, he's 25). We decided to stay in contact, because there was no huge fight/cheating, etc. I truly want him in my life, too. However, when he called me last night, I broke down into tears after I got off the phone.. Our conversation was friendly but I could tell it was a little awkward. I'm sure his feelings for me didn't immediately disappear already. I can't suddenly put my feelings to the "off" position.. I decided to write him a letter. I poured out my heart & told him I love him (had not said that yet, I'd always chicken out) and wish to meet up in late february or so to possibly revisit the relationship & see how we feel. I asked him what he thought & to please contact me.. Originally I was thinking we could just be "friends" and then ease back into his life. I don't know if I can do that & I'd be more devastated if weeks/months went by and then be crushed bc he doesn't want to start over then. I guess if he doesn't want me, I'd rather be crushed sooner rather than later. Did I do the right thing telling him how I felt & being honest? I decided I'd regret it more it if I had never told him I loved him. In my letter, I did not beg / plead, I simply asked him to rethink what he's had & for a fresh start. How long should I wait for him to respond before I simply give up & move on? I suppose if I get no response then maybe he doesn't love me after all. I am aware that you can't force someone to love, but I do know he has some feelings there as he dated me for so long. We have something that is salvageable & wasn't going to let this go down very easy.. I thought I was going to marry him! I miss him so much.. Thanks for input.