Guys.. advice please?

Just this week I found out my guy was trolling online dating accounts. The day after I found out, he decided that we are broken up. When I asked questions he says that it's because he no longer loves. What you need to know is, we didn't even argue about it. It was a civil sit down conversation before I was no longer able to let the years fall down my face. But still never any yelling. I wanted to deal with it like an adult. We have been living together over a year. I know work has him down, but other than that he's never mentioned that we were in a bad place. We have been so good, and right up until the day I found out he was still his goody, kissy kissy and playful self. It's so out of character.
Why would he does this? Why wouldn't he have talked to me? Why isn't he giving our relationship a chance, he's just giving up? We have our house and life together. He now has literally nothing but his computer now.
If he would actually talk to me I maybe could get answers, but that's not working either.
just a loving girl who doesn't want to lose her best friend and uproot her life :(
Guys.. advice please?
Add Opinion