My boyfriend dumped me after 3 years

So yesterday my boyfriend broke up with me after being with me for 3 years. Last week he sent me a text asking if a screen shot of a message was me. Which the screen shot came off of my phone. So how did he get it?? The screen shot was of a joke my best friend and I had and he even knew about it. He claims I showed my tits to another guy which never happened? And every time I explain to him the joke and what happened he said he never believed me. Apparently he has more screen shots from my phone that I don't know how he got, which I thought was strange. We were long distance (I'm in KY and he's in PA, but I used to live there). But he claims someone has been sending him stuff of what I've been doing and claiming some one else got my messages off of my phone. Which is an extreme invasion of my personal privacy. I would have never had anyone send me stuff of what he is doing because I trusted him. I feel so hurt and invaded. I would never cheat on him or anyone. I had planned my life according to how he wanted it and now I'm not too sure what to do with it. He hasn't texted me, but he snapchatted me at like 5 this morning.