It sounds like you are starting to see that there is life off the crazy train. That's good!
I remember one of the things that helped me step off the roller coaster the first time my H left me was when I realized how flippin' crazy he had become!!! And not in a sour grapes "If he doesn't want me, he must be crazy" sort of way.. actually "not playing with a full deck of cards" nutso.
When I told H that I had contracted an STI from his OW#1 (chlamydia), he told me there was no way that was possible because he had not been sexually active with OW#1 yet. (Of course, that wasn't true.. as he admitted years later.) I told him that I had never had any sexual partners but him so there was no way that my STI hadn't come from him via OW#1. Nope.. H would not accept it. Said OW#1 was an angel and was not infected. (OW#1 had a bad reputation years before H ever met her.) Then he told me that I must have gotten the STI from the hospital (because that place is full of germs, he said) when I had our daughter.
I stared at him... and realized with dawning horror that he believed every word of nonsense that was coming out of his mouth.
That night I realized my H was on a crazy train and I was riding in the caboose. That night I got off the crazy train.
Your W, dear friend... is not herself. She might come back.. she might never come back. We can't tell the future. But she is riding a crazy train right now and you can't ride on that train with her... it's destroying you!
Keep your head high. GAL. Find out your rights on how to obtain more time with your son. In every way possible, every day.. even if it's in little ways... move forward.