I know exactly how you are feeling right now. I am in the same place. I've been going through this with my AH for six years now and he relapsed again over the summer after a year clean. It's been ongoing since then, including the day our second son was born and lots of days since.
Last week I had to ask him to leave for a few days and I felt great while he was gone. Well, not GREAT but I had some serenity. He came back and within 20 minutes I felt horrible again, all my serenity was gone and my instincts also say he's still using (so do his stupid eyes).
I'm in counseling trying to get the strength to ask him to leave once and for all. I have two kids with him but what mostly hold me back is the fear of being apart from him.
I don't have any real advice except for keep doing the things that helped you feel better while he was gone. Ie, calling your sponsor or going to meetings.
Hope you are feeling better soon!