I have to second Divine that if there is any hope of saving your marriage, you need marital therapy now, not with the next blowup. It will be too late by then, as you stated you can already feel yourself emotionally withdrawing.

You also don't have to tell him what your reasons are. Just tell him it's best left to discuss in therapy, but they are for the health and happiness of your marriage.
And the bottom line is, therapy may just delay the inevitable anyways.

From what you've posted, he just doesn't seem to be a good fit for you. He sounds like he would be happiest with a sugar mama. Someone taking care of him, doling out his weekly allowance like a ten year old. And I'm not making that wrong, there are women willing to fill that role, especially if they are lonely and rich. They both benefit in their own way. They're using each other, but they're both happy and know it for what it is. He'd be her pet.

I would also like to point out that you want to save money to move. This is a question for a lawyer, but that could be considered joint money, as it was acquired during the course of the marriage, and he would be entitled to half of whatever you save. It would be no different than when a man makes much more than his wife (which sadly is often the case), socks a bunch of money away, divorces his wife, then tries to keep all that money for himself. Judges won't often agree to that.
You will have to look closely at whether it's better to move out using credit, or save knowing you may only be able to keep half of it.

I also acknowledge you seem to truly love your husband, you just don't like him. That makes it very tough.