How do you make him understand

Laura • Laura lu
When I try to tell him something that I don't like or that he needs to change he thinks that I am yelling at him. I am not or I try not to but it seems like that is the only way that he understands or gets through to him. It makes us bitch about stupid things so it seems like we are always fighting. I also think my housing situation and disability get in the way. What should I do? The one big factor as well is we are super sensitive PSTD victims/rape and I hate that that gets in the way. 
This is when we were happy