husband doesn't feel like my husband

A little back story: husband and I have been married just over a year, in a relationship for almost 3. We met online and at the beginning of our relationship there was lots of drama over his exes. He still talked to all of them regularily among other things.
I felt like this amount of contact with every single ex was weird and inappropriate (so much happened, too much to tell but texts on valentines etc) 
Now we are expecting our first child, he is out at his bffs bachelor party and I'm chilling in the hotel using his computer to watch Netflix, he got an email confirmation of the gift we'd given and so I clicked on it and then noticed a bunch of folders marked "personal" or "family" or "friends" etc. so I go into them and in the personal folder I find 17 emails between him and some girl he apparently hooked up with while he was with one of his exes. The emails are from years and years ago but I can't believe he would do that and also the way he was talking doesn't even seem like my husband. 
Down the rabbit hope I went and found a bunch of emails either with his exes or his parents or friends about his exes. In all of this it is like I'm reading a strangers emails, it just doesn't sound like my husband. 
He also told me a long time ago that he got rid of all the emails with his exes but clearly there are still some there and they make me sick. I feel like I don't know him. I thought we were at the point of not having any more secrets and being open, but I guess not. I don't know what to do but I'm super stressed and sad.