What should I do?

Hey guys, I've got a tough question that I really need some advice on.
I've got a bit of a background story that I have to explain first, so please bare with me.

My boyfriend and I have been dating for 6 months now, and have lived together for the past 4 months.
In the beginning of the first month of our relationship, I had been goofing around with him one day and popped open
his wallet to see what was inside. It was all pretty usual wallet-type stuff, aside from the picture of a girl inside that I
had never seen before. I asked him about it, he said it was a friend from highschool, it was her senior photo that she had
given him upon graduation. This didnt really bother me at the time.

A couple of weeks later, him and his best friend were contemplating moving out of the state. I butted in and said I wanted to
go with them, and as a result got a very strange look out of my boyfriend. After begging him to explain the look, he
told me, "well, knowing me, I'd probably beg and plead for alyssa to come with me."

That stung. And guess who alyssa is? Yes, the girl on the photo in his wallet.
I was upset. He apologized and explained to me that she was his first love, and it was hard to let her go.
I made him get rid of the picture, and he proceeded to rip it up in front of me.
You could see the pain on his face while he did it.

A couple of days later, while cleaning our bedroom, i found his journal. Inside, were years of entries.
I skimmed through it, for a few seconds, but it was long enough to find out how intensely he felt about her.
How much he thought about her.
I never told him I read that. I figured I wouldnt bring it up unless something else came up again.

About two months pass, everything is going great. We moved in together. Haven't heard anything about alyssa in a while,
so I assumed it was all over.
We went through a whole lot those past months. Near death situations, emotional rollercoasters, but we fell in love.
He told me he was in love with me, that he had finally found the love he had always been looking for.
And of course, I am in love with him, more than anything in my entire life.
He is amazing. He treats me like I've always dreamed a guy would.
I know he loves me, I can see it in his face, and in his actions. I know he's not lying when he tells me that.

Well, sometime near the end of 3 months, we had just gotten back from a party.
We got home, and had one of the most passionate love making sessions ever.
It was amazing. And I was feeling pretty great afterwards.
That was, until I looked over and saw him making a strange facial expression.
He told me it wasnt a big deal, grabbed his journal and began to write.
I let it go, and went to bed.

The next day, when he went to take a shower, I knew I had to see what he was writing about that he couldnt tell me.
I opened it up, and there it was.
"we just made love, but all i could think about afterwards was how much i miss alyssa. im sorry baby, i'm sorry i cant tell you. i wish it wasnt like this. blah blah blah"

After that, I scribbled a note about how I had read that, and left the house. I came back a few hours later to find him bawling. We layed together in bed, not speaking, and only crying together. After that we had a long talk, about how he only wrote that because he couldnt understand why he was feeling that. He didnt want to feel that. He wanted to be with me. He loves me, not her, is what he said.

I believed him. I forgave him. After all, he had been through a whole lot more with her than he had with me, I can't hate him for having memories, can I?

After that, I told him I didn't want him talking to her anymore, via email, facebook etc. I told him to delete her as a friend.
And he did. He blocked her so she wouldnt wonder why he had deleted her.

Well, here we are now, six months into our relationship, and last week he had gone to work with my cellphone, leaving me stranded with no way to get ahold of him. (he doesnt have a phone). I tried texting him through aim all day, trying to figure out when he was going to get home from work so i could go pick him up. After trying for hours, i was like... hey I know i have facebook notifications, why dont I just send a message to myself from his account and it will be sent to my phone and I can get ahold of him that way!

Well, upon logging into his FB account, and opening the inbox, guess what i see? Yess, thats right, a lovely conversation, started by him, with the beloved alysssa. And in that conversation, he had even told her that the reason he hadnt talked to her in a while was because i was jealous. And also told her that jealous tendencies are stupid, and that i 'dont even know anything about her'. and that he is so fond of his memories with her.

What kind of crap is that?

Here is where my question comes in.

What the heck am I supposed to do?

Any advice is most appreciated. Sorry for the typos. It's been a long day and I"m tired.