Help!!

Ok so I live with my boyfriend and his mum. Everything was well for months and then suddenly she starts to blow hot and cold with me. She shouted at me for having a shower as she was about to have one (but didn’t tell me) I wouldn’t have mind to wait! And then a few weeks ago she texted me when I was in work going off in one cause I used the washing machine to clean my uniform as I had no clean ones for that day!!! She nags over little things to me like not emptying water bottles before they go in the bin. Its not a big deal!!! 😩 I dunno how much longer I can live with her for as my boyfriend thinks we need more money before we move out as he doesn’t want to rent he want a mortgage (where we own our own house forever) but I need out I’m going mad & so ready to rock her fucking jaw 😃👌🏼 what should I do!!?