Am I fighting a losing battle?

My fiance and I have been together for two years.I was single for six years after a horrible divorce from a husband who was addicted to drugs. And previous to that, my husband(children's father) lost his life abruptly from meningitis. I had vowed that I would remain single for many more years to come. But I fell in love with his sweet ways instantly. He cooked for me and cleaned for me all the time when we first met. Now as far as housework goes, I do it but when I get ready. For example, If I don't wash clothes every 2-3 days he gets mad and tells me I'm worthless. My house is not filthy but sometimes I have mail that piles up when I don't file them regularly. We don't leave dishes in the sink overnight but sometimes we have a couple but no major stuff with food in it. Well time went on and things started getting better(that I knew of). We started going places and doing things(I admit mostly at my expense) but when you love someone you don't always look at their finances and judge them by that. As time flew by, we started living together. He has become a very mean and aggressive person. I have had a dog like 2 yrs before I met him and now I'm nasty because I have a dog in the house. She is not allowed in the kitchen but she may put her two front paws on the hard floor trying to be sneaky and he gets livid. Every time he asks me to go do things with him(with the exception of the convenient store) and sometimes family or friends, I go. He wants nothing to do with my friends/family. My best friend and I have been there for each other for over 13 years. I was there for the birth of all her children and I'm the only aunt they know because she has no siblings. Her mom passed away two years ago and now I'm all she has(outside of her husband & kids). We never hang out anymore or talk on the phone like we used to. We still talk maybe like 2 times a week versus when we used to talk about 7-8 times a week. He swears up and down that we are intimate with each other and it makes me sick to my stomach. My bff is married, and very happily married and in love with her husband of 15 years. Her husband is like a brother to me, he always makes sure that my kids and I were okay. If I mention dinner with her or anything, my fiance goes completely off! And it's not just her but anyone. This really hurts me BAD because I have no relatives here where we live and all I do is sit home everyday. If I say I'm going to Wal-mart or somewhere he always does everything he can for me to wait until he gets home so he can drive me or just be with me when I go. I have children who are teenagers(he has no children), he complains about everything that they do, don't do or even may do. He said at one point that my daughter was outside "soliciting" just because she was standing there talking with her friends(girls). My daughter is an A student who works hard and is very respectful of him. Now my son could surely do better than what he is doing, he just turned 18 and still has a lot of growing to do. I am always there for my children and my fiance also. I have "always" had his back. But everything that I do and say, he has a problem with it. He has now started calling me a whore because I argue with him about going to a girl's night out, lunch or anywhere without him. He even told me that if I did try to go out with my friends that I would have to be home by 7:30pm and bars and clubs were surely out of the question. I try everything that I possibly can to make him happy but it seems like he notices when he makes me feel bad and then just plays on my emotions. I have become very depressed and sometimes I feel that I can't focus the way that I need to. I am very angry with him sometimes and when he says such ugly things I tend to say ugly things to him back. I'm usually not like this but I feel that he brings it out of me sometimes. I am very defensive towards him and I shut up sometimes in hopes that he will do the same. He has said some seriously ugly things about me that I just can't believe. The only reason that I am writing this is because I have kinda lost myself and trying to find my way back to self. I'm just trying to see if it's just me being knucklehead and not giving him a chance. He has been abusive physically as well and sometimes I fear him but then sometimes I get strong-minded and stand my ground but I never hit him back. It's sad because we argue about stupid things like he said that I didn't shut his car door right. He said I should have used the handle and not touch anywhere else to shut it. He is always telling me that I'm a bad mom and he doesn't agree with the way I do things. I try to keep a good relationship with my children because I want them to feel they can come to me with anything(not friends). We argue most of the time because he keeps saying that I don't love him but I try to explain to him that he needs to