I need help

I just saw my fiance's texts with his mom. She was talking shit about me and he wasn't defending me. I moved in with him 2 months ago, he still lives with his mom. I'm 18 and he's 20. For some more context, last week I had a terrible stomach virus. I couldn't really get out of bed or eat or drink without intense stomach pain. I didn't shower for 2 days because of it. I only went out of our room once. He works 6 to 5, so I was alone in the house with his father. 4 days ago I saw his mom calling me a Weiner for calling in sick, I work with food, so it's required of me. My fiance hates to clean his room, so it's littered with empty soda cans. His mom loves to clean. She always blames me for it, even though I told both of them that I will help clean it, I just won't do it myself. An hour ago he was real secretive on his phone and I took a look. His mom was saying that I'm nasty and dirty, I don't shower and I don't clean, etc. He wasn't defending me, at all. He hid his phone from me. And won't let me read any more of what she said. I'm lost. I'm moving back with my mom tomorrow, I haven't told him yet. We've had problems like this before, and he never defends more or anything. I understand that's his mom but...I'm his fiance. We are supposed to get married next October. I hate confrontation and I know if I say something his mom will yell or do something worse to me. I just... Don't know what to do...I love him but...this keeps happening. Am I overreacting?