It's hard when you're ambivalent about him leaving.  And the A being gone seems to leave room for all the good memories to come surging back.  I remember the day my A moved out (because I had asked him to), after many months of terrible behavior on his part, passing out, lying, breaking promises, and all that -- even despite all that, on the day he moved out I had a panic attack that I was making a huge mistake.  The unknown was so scary, and I remembered so many good things about our relationship (most of them long in the past, sadly).  And him not being present allowed all the fantasies I had about things changing and our being happy again to come to the surface. 

After things had calmed down, I found that I really appreciated living without the turmoil and the chaos.  But just as it's hard for them to give up alcohol, it took several years of false starts in the years before that for me to give him up. 

I don't mean to tell you what you should want or what you should decide.  One thing that helped me was writing down all the good things and the bad things, so I could look at the list when I was feeling confused.  I tended to black-and-white thinking, like it was either all good (I'd discount all the bad things) or all bad (as if we never had had any good times).  And then which has it been lately? 

Hugs to you -- take care of yourself.