Being strung along and hurting

My fiancé seems to think that because he works hard to support us financially, and that he loves me and wants to be with me forever, that that should be enough for us. He proposed to me in 2018 and we’ve been living together since 2015. He’s always said he wanted to marry me, but I don’t know why he hasn’t done it yet. He just keeps saying it’ll happen soon, and gets mad when I question what that means to him, and he’ll say things like “why can’t we be just be happy” or “do you think we’ll be better off married!”. We are in our 30’s and both have full time jobs, and live together. Am I just a failure of a woman? It really hurts to know that he’s basically strung me along and I’ve allowed him to do it. I love him and can’t imagine my life without him, but he’s lied to me for years and it makes me wonder what else he’s lied about. He’s lead me to believe he’s wanted to marry me but his statements and actions have proven otherwise. He knows marriage is important to me and he’s lead me to believe the same over the years. I am hurt and confused to say the least. 😢