What should I do? Boyfriend problem he's ignoring me. it's rly long, but I'm desperate plz answer?

I'm 18, my bf is 16. I live in washington he's in NY state. neither of us care about . we video chat and text and talk on the phone. i know he is who he says he is. We even IM. well, we used to. a while ago I kept getting distracted by things like YouTube videos and messing around with audio and stuff and I was like not replying to his IMs and when I would replky I was short with him. like he says this long story or something and all I say is lol or XD or something. we had a talk and I triy my best to stop doing that. I know I've at least cut back a lot on it. now he's doing the same thing to me and it sucks. no, he's not trying to make a point. just he's on IMVU which is like a virtual world like second life or something. he spends moe time on it and with his virtual gf than with me. (he's bi) I know nothing's going on, like he's not cheating on me or anything, because I trust him. also I wouldn't have any problem with it if he was. I just wouldn't want him to lie about it. It just sucks because I'm trying to lose weight all day (I'm a bit chubby) and he's bored without me online all day so he has to do stuff to occupy his time. I have a phone but I'm with my mom and she's so awesome and distracting that I can't carry on a text conversation. but at he end of the day when I finally am on, I try to IM him and there's no response. 5 minutes later I say "?" and he says "brb" and I say "k". 10 minutes later I say "?" agian and he says "I gtg" and I'm like wtf because my feet are killing me from walking all day to try and be healthy so when I come see him I can be skinny and if we do sdecide to *ahem* "do something" I won't disgust and crush him. then I get home and all he says to me is brb and then later I gtg?? It annoys me and it upsets me. I want to talk to him more but I can't because he's always on that damn imvu site. Oh, oh, and get this. I tried to sign up for imvu just so I could at least talk to him or something, ansd he says he's not gonna friend me. It's not a big deal, I know. but still. Do you think we need to break up or someting? We took a break for a bit and it seemed to work but now he's ingoring me worse than ever. =( I'm one of those people who get's attatched easily and break ups are hard for me. i don't cry, but I'm incapable of admitting to myself that it's over. I'm incapable of moving on. if we do break up I'll still do the same stuff I do now. I'll still IM him and say I love you and everything. I just won't go see him irl if we break up. oh and we've been together for more than a year. infact a year and a half.