<human>: Give me the gist of the text in a nutshell

A bit of history: we met at work one year ago & hit it off immediately.  He made it clear that he was in an 8-year-relationship but was on the way out.  In hindsight, I should have hot-tailed it then & there with a 'call me when you're on the market, bud', but I didn't.  

We work 10 days on, 4 days off.  We actively started dating.  We've always been able to communicate about everything.  Except, I noticed 6 months in, she (the ex) didn't come up in conversation.  Ever.  They had a house together which he never went to.  We were so caught up in each other that I completely forgot the circumstances & just assumed they were done.  **Naive little mistress**, I know.  He spoke of a future with me, of putting me on a mortgage, having kids.. all the white-picket fence stuff.

But ever since October, things have been different.  He's gone back to their home every time he's not at our 'work' house.  He spent the holidays with her.  I found out I was pregnant in January and he wouldn't come home to help me through things.  I miscarried last week and he went scurrying back home to her a week later (on his days off work).

What the hell should I do here, guys?
The more I type out, the more obvious it is...
So I guess what I'm really looking for is some sort of support.
I've been to a therapist, I've been honest with the other woman...

I just need to stop caring about this guy & can't seem to do so.
I've got my whole life ahead of me & I'm just stuck.

Be harsh, be kind, be honest.  Just looking for a nudge here.
<bot>: Girl meets boy, boy bounces between new girl & old girl.  New girl gets pregnant, miscarries & after a blindingly obvious lack of support, can't find the gall to leave boy.