Is the writing on the wall? Please help! Newbie

[lost'em]

Hmmm, so I've been lurking around here for months. To finally reaching a point where I have to ask for help. I've kept a lot to myself, and my friends I have probably heard enough about my situation. I currently and living 100s of miles away from home
So here it goes:
He and I had a world wind romance. I meet him 2008, and we were married in 2010. We were the best of friends, and madly in love. About 6mos, after we got married, H got a new job, and we moved across the country (away from my family and our friends). His family lives in the UK
Honestly, that's where the problems began...he left me for 2mos and moved here, while I settled our finances at home. He has one friend who lives here, and was also recently married. Fully believe that my H is in a full blown MLC. Almost two summers ago (2011) he had severe migraine (we never got a 2nd diagnosis). Which caused stroke like symptoms for almost 2 days, he lost his motor skills. It was the scariest of time...out son(step) was also here. Once H was released from the hospital, in retrospect he was different. At the time, I couldn't put my finger on it. However, things were different (it's also a reference point for H)
Fast forward to the holidays, we had a major fight, and couldn't seem to recover from it. I felt like H was not available for me, and it made me desperate and angry, which of course led to more fighting. Started to feel as if, he wanted to spend more time with his friend than me. Which of course led to more arguments. I think you probably get the idea

Over the spring, he started staying out all night, drinking excessively, and also smoking. H started to grow his hair out, because he was taking inventory of if he was growing any bald spots! I was so bewildered by his behavior, and was confused as to where my loving husband went to
Summer happens, and step son arrives. I was hoping that this would be a stabilizing force, but it wasn't. H would get the little one, ready for bed, and then head out for the evening. Wouldn't see him until the next morning, where he would show up for breakfast (and pretend like everything was normal).
Everything hit the fan, when my circle of friends found out that H's friend was cheating on his wife. We all shocked, esp my husband! He gave his friend the harshest conversations! He was so angry, with him. This should have been a sign for me. A few days later, H told me that he want a separation to sort out his feelings (via text message)
He was growing increasingly angry, lots of outbursts, lots yelling. In general, just escalating. After educating myself, I guess this must have been the Anger stage. Eventually, H got his way, and I left to stay at a friend's house. I was gone for exactly 1 week, and the whole time he has said that he just needed some time. I discovered during my week away that H was having long ext conversations, I did some PI work and also found some inappropriate email exchanges. A little research, and found out her name, she worked with him. Surprise. I found enough, and decided I also had enough and decided to go back home. Walked back into our place, and there was wine glasses, shower with hair in the drain, and overnight bag(w/ magazine with her name on it).

I confronted H, and of course he denied it. Said that they were friends, and more than few people were staying there. H also said that he felt free, as if a weight had been lifted, and he wasn't going back to the other way. He started saying that he didn't love me any more, and that he just wanted out. Escalated fights again, and for my mental health. I left in October. I have been working on myself, volunteering at a school, and I just got a new job. Practicing DB, and GAL

Nov, we had little or no contact, only conversation about financial matters

In Dec, he sent me some crazy text messages (just spewing hateful things).

Jan, he wanted to sit down and talk. Turns out, that he wanted to start planning our D. I said that I wanted to work on our marriage. He was surprised, and repeated what he said before(he wants to be free, doesn't love me anymore) etc. he was like let's talk again in 30 days

Feb, our conversations have gotten much better. No more angry spewing. A few weeks ago, he told that was laid off from his job. We just sat down tonight. Which is probably, why I up at 5am. H said again, that he wants a divorce, and tried to get me to sign papers over coffee. I told him no, that I didn't agree with this. I didn't think we were handling this properly, and I was standing for our marriage. He laughed and told me good luck, and that he was happy now. He said that he was on a journey to discovering himself, and that time was running out for him to be happy. H doesn't want to spend anymore time being unhappy or sad. He looks like hell, and wreaked of tobacco. His eyes were bloodshot
I think the writing is on the wall, but I was hoping that someone could help me. I am really struggling. He told me that he was going to file soon. This is H's 2nd marriage, and I think he filed the 1rst time too. I'm sure that it's MLC. Any support, or just advice would be amazing! What should I do? Please help