When to call it quits

I have been married for 14 years and have 3 wonderful kids. We were young parents and have always struggled financially. Lately I feel that we are two different people. I guess deep down I always felt this way but I keep hoping that someday he would grow up. I grew up with values that marriage is meant forever and you don’t give up. He is a wonderful father, but we don’t always see eye to eye. We always argue about money and his mother has always lived with us. I love her dearly but she is a difficult person. She is always butting in on everything and that causes more tension. He is an only child and I grew up being very independent at age 16. I don’t know how much more I can take. I try to communicate and tell him how I feel without hurting his feelings but he never thinks there is a problem. I feel like all the weight is on my shoulders because I always worry about the kids and bills. I am always the one fixing the problems and taking care of the finances. We both work but he doesn’t see eye to eye with me. I always say that if we don’t need it, we shouldn’t buy it and he doesn’t think twice. I consider myself to be a great mom, hard worker and good wife. I am the type of woman that works full time and is still takes care of family and house. I am getting tired of doing it all at home. He always tells me that I clean too much and that I worry too much. I always tell him that he doesn’t know how lucky he is. Someone has to be the adult and I feel like I have 4 kids not 3. There are many times that I don’t see him like my husband. He is a good guy but I wonder if he will ever grow up. I don’t know what to do. Is it normal to think that my life would be better without him? I know that I am not perfect either. Even though I am married I feel lonely.