Your post rings so many similarities with my situation.
My ex left the week before Xmas (well he would say I chucked him out).. So I'm nearly 3 months down the line. It occupies most, not every, of my daily thoughts still- this Is progress!
I similarly am so sad, even though it was so bad when he left. Illogical, right? When he left a weight was lifted. I didnt have a highly dependent person to look after, I could focus on the kids. But I was so sad, particularly when I found out after he had been cheating on me (which I never thought he would have done) - it really floored me, which was so annoying as I had been doing so well for the first couple of weeks!
Similarly he was alcoholic and emotional abuser. And soooo lazy! It got much worse when I was pregnant last year- I posted here April 13 and the response I got from MN-ers was 'leave now'... But I couldn't give up my family, I wasn't ready to hear it (i have since updated my post so they know i am out of it!)I kept trying and trying, blaming myself, covering it up, Keeping it a secret. Typical co-alcoholic.
I have read a good book recently, a lot of which I think "that's me". It's called "women who love too much". It's definitely worth a read. I always focused on how great the future would be, how with my love and support he would get better and we would get to the happy ever after- I now know that this never happens in these situations
I put up with it for a long time. I could still 'stand it'. But I know now, I deserve better than the worst I can stand! And so do my kids.
I am not ease yet. I am angry and in shock still. It is difficult doing the parenting all myself (he has disappeared out of their lives, he has had a complete breakdown).
But I know I could have easily wasted so many more years. I'm glad I'm out!
I have written down messages for myself - this one might ring true to some of you
"Never let someone who contributes so little to a relationship, control so much of it"