Stepdad kicking us out

Short back story..

My mom got married to her boyfriend of 8 years early this year. Mom and I lived together in my grandparents house until they kicked us out. We moved in with her husband and everything has been shit since.

Today he stated he wanted us out. He didn't want the cats or the mess and there were to many people in the house. The house is a 3 bed 2 bath. It is small for 6 animals (3 dogs 3 cats) him my mom my son and myself. There are a lot of baby items scattered around the house by it's not messy.

I have a place to go. I have a wonderful boyfriend who would love to have my son and I live with him. He already treats my son as his own. I can bring my dog and cat as well.

I've also got friends whom I could stay with but I wouldn't be able to bring my animals.

My mom tells me I need to ask my aunt if I can stay with her but I honestly don't want to. She tells me I'm not going to live with my boyfriend but honestly she can't really stop me. I'm 20.

I'm not exactly worried about myself and my son as I know we will be okay.

It's my mom I'm worried most about. She doesn't have money and her car has a major computer issue that can't be fixed. Since she's married she can't get government support. She would have to surrender her cats which I know would absolutely kill her and live in her car. Her husband would keep two dogs as he loves them...