Is normal to feel this way?

Ok, so I have spent the last six years in a relationship that has gone from violent and hostile to volatile and stale and is currently in transition to hopefully good, IF and this is where I need help I can pull myself together. I am bitter and angry, I am these things towards my sons father for hurting me, I am angry at him for doing things to me when I had so much to care for and deal with while he was out having an addiction and leaving me when I needed someone the most and I am now angry at him because our sons don't know (and not that they should) how badly I was treated and they now blame me for our family breakdown,I can't tell them the truth, it wouldn't make any sense to a 5 and 6 yr. old and I would be a ahole for trying. Due to the fact that I allowed my whole world to revolve around him and his temper, I have no friends, I moved across the country with no family, not that it would help, their pretty messed up too. I feel extremely alone and I have come to realize that I am codependent which makes me even more upset, I don't feel fit to be a mother, and this is relfected to my children, I am short tempered and have no patience with them, I want desperately to enjoy them again but they are constantly saying I don't care, I don't listened, etc. Which only angers me more, because it was I that takes them to doctor appointments, the movies,the pool, their friends, plays board games, does art projects, finds the things they really want, makes sure they do the fun stuff all kids should be doing, It's me who has stayed in this rotten relationship because they love their daddy and even though we don't get along he love them, I feel I have done all the work and he is getting all the credited cause he's nice, while I'm the one that has to take them to the grocery store,bank, the liabrary, and listen to them talk back, and say stupid things he's taught them, I feel I have no control over how my kids are being raised but I am the one that has to deal with the people they are becoming, sometimes and most days lately I just want to walk away and start over but I know I can't, I feel like maybe they would appreciate me if they weren't with me ALL the time but it's impossible to do, with him living out of suitcase and I feel guilty though I shouldn't, I deserve to feel angry, I deserve to have time to myself and grieve my life so I can be better, don't I? how do I begin to get better when there's so much daily I responsible for and how do find patience with no time?