I need advice and opinions?

I just need honest outside opinions because I am at a lose, This may be long, Im not sure yet. This is my first and only marriage. My wife has four children by 3 different men, I don't have any children of my own. Our problems started when I moved in and realized that she gave all the children a shower at the same time, they would stand in line in the bathroom while she ran them through the shower. The kids are 16, 13 and 10 Twins. 3 boys and a 10 year old girl. I have also found her in the bathroom completely nude while her 13 year old boy was in there. I brought it up to her and said that she can't be doing that anymore and she called me a pervert and hit me, ripped my shirt off and clawed me up till I started bleeding. She did this several times, I have never hit her, I would sit on my hands as she hit me in the face repeatedly......Going past that, She has told her mother and anyone that will listen that I am abusive and that I have anger issues and lots of other derogatory things. They take family outings and I am not invited, my wife tells me that I cannot come because they are going over to her mothers house and I am not welcome there. They go to church without me and tell me that I cannot come. She lets her kids say whatever they want to me, no matter how disparaging. Her 16 year old, just tonight called me a F*in Prick in front of her and she told him "Good Job". They are going on vacation in a week and my wife told me that I cannot come, that its a "Family" vacation. They spent last Christmas, thanksgiving and new years without me because they left the house and told me I couldn't come. All of this because I thought what she was doing is wrong.....I just need some advice on what to do and if this is normal because this is my first and only marriage. I say only because she gave me herpes and I cannot move on to someone else and marry again, I will never have children of my own because she has had her tubes tied. She also wont wear her wedding ring. Sorry if I was long winded.