Confused

I find myself thinking about separating from my husband, we have been together for over 20 years, but I just don't think I have the energy or the will to continue. On one hand I know that I blame him for a lot of my unhappiness, but that also he doesn't see my side of everything as well. I work and keep the house going and have no time for anything else. He has several hobbies and outings, in fact he is gone for a week right now on a trip. He isn't gone a lot but he has done several trips and I have done none. I feel very alone in most things. I feel like I have no support in most things. He isn't a bad guy really, but I find myself mad at him most of the time, when he is gone, there is peace in the house, I am not as cranky with kids, there is a lot less yelling.
Even reading this is sounds lame, I just don't know what to do! I feel so much stress all the time, and find I am just thinking in circles!