Rock bottom

So I moved in with my mom last year to help her out, she wanted my son & I to after my divorce and claimed she wanted to help me. Fast forward it’s been hell, she hasn’t helped me not once, I do all the helping. She even made me lose my job with her toxicity. She may be mean because she is getting older health not as good but It’s not healthy for my son. I have money saved but can’t get a place with no income coming in. It’s not the money it’s my moms verbal abuse in here towards me. I want to leave so bad but no longer have a job & we are in a small town where childcare is full. She OFFERED to keep him prior to coming here but lied about that. I was doing so good and came here to help her now I am struggling.She yells every day and it’s harmful to my son. I signed him up for summer camp and was feeling some relief to get back to work, but my last straw was they cancelled it for 3/4 year olds this morning. Idk what to do, my brother says my kid can come there but I hate to do this, I was a stay at home mom when married & I will miss him so much. My brother lives 6 hours away! We both can’t come, I know I gotta do what’s best for my baby. Am I making the right choice??