Just wanted to say, my friend, that you took a big step that you were ready for. And I agree that your wife just keeps making excuse after excuse.
So, see what you can change, what you want to change, then see where you wind up.
In the end, she has to make the decision that is best for her and you for you.
All in all, this was a positive step for you.
I hope and pray that you get what you want and that she finds out whatever it is that is keeping her so tightly wound.
You could mention to her that you could get a mattress that requires no money down and then I would let that one rest. Clearly it is not the real issue and I do think pushing it will just get her angry.