I am curious as to the details of getting kicked out of “your” house. I am not familiar with the legalities, but advice I have seen is that if you leave you are at a disadvantage. It is often suggested that if she wants out of the relationship, then she should leave and you should stay. Of course that depends on who the house actually belongs to. But you said that “she began to move in” which implies that it was your place to begin with. Given that, you leaving was probably a mistake.
I am also wondering if postpartum depression is part of the issue. Have you discussed counselling?
Now, of course, the pandemic makes this even more challenging.
Under the circumstances you may have to rely on the courts. Document EVERYTHING in detail! What has happened so far and what continues to happen.
Have you asked her about seeing your son? What it would take to make it happen?
If she refuses, tell her you will take her to court.
Best of luck to you.