relationship

Honestly I don't know where to start. I put this anonymously as I just want advice. 
I honestly don't feel happy. My fiancé and I have been together for over a year now and have been trying for a while. I don't think that I should be. Every day we argue. We fight about the smallest of things but it puts a massive wedge between us. I don't want to be near him. We broke up and he just wouldn't leave me alone. So I caved and we got back together. 
Not only is it the relationship that's toxic but my behaviour since I began to (I'm going to say it but I don't know if it's true) fall out of love, but I have no motivation. I'm training to be a midwife and I can't be bothered anymore, I don't care. All I want is to be away from it all. 
What should I do? I don't want to hurt him but every time I talk to him about it, he keeps trying to fix it. Every time we "fix" it. It's broken a few weeks again. I don't want to be like this anymore. I don't want to live like this