@Scaffoldtothesky I mean this with kindness, but I feel so frustrated reading your thread.
Your husband shows you no love, no care, no affection, no respect, he doesn't listen to you, he doesn't care about your feelings or opinions. You are a non-person to him. He is contradictory, changes his mind, makes no sense, refused to discuss issues including this very important one. It appears the only reason he wants you around is so he can tick the box 'son lives with both parents'. And possible because you're handy as you do more of the work and planning, whilst also earning more.
Why are on earth are you considering for one moment staying with him? Your life would be immeasurably better without him.
Your son would without doubt be better off too. Your relationship is a very unhealthy one which he will see as a model for his future relationships. I'm sure you don't want that for him. He lives in a house where there is tension and no love between the adults. That sounds awful for him.
If you stay, you will continue to feel as though you are disappearing. You will becime less and less you. Your son won't see the real you anymore. Your life will have been wasted.
By leaving you will find yourself again, you will be able to live in a loving, warm, calm home with your son. OK you won't see as much of him as you will be co-parenting, but your son will have his mum back. You will be stronger, happier, more resilient. You can be happily single, or, in time you might meet someone else. Someone who loves you and cares for you, listens to you and respects you as his equal.
You don't need your husband's permission to leave him. You can find somewhere else to live and leave with your son. Of course you will have to agree a co-parenting arrangement that is fair and best for your son. Perhaps that should be the focus of your future therapy. But if you keep waiting for your husband to make a decision I suspect you will wait forever. And besides, why does he have to be the one to make a decision?