I used to have a pain in the rear ex husband like this, I am sorry you are having to go through it too. Above all things, protect yourself and your child that is the most important thing. If you can find a way to keep him out of your house, that'd probably be a good thing too. I know from experience, sometimes it's hard to get these situations straightened out. Hopefully he'll find someone else to distract him and leave you alone.
I agree with the others, finding some domestic abuse counseling might be a big help as well. Controlling men should have to wear a neon sign over their heads to warn us
They're so good at hiding that character flaw until they feel they have you trapped..then blammo!
I hope everything works out for you, and keep on track with your plan..the best revenge can sometimes come in the form of doing what is best for ourselves and feeling great about it. That kind of revenge is a win for us in the end, no negatives there at all
Take care and be safe,
Boosk