Oh, my dear, my heart breaks for you. My first husband was like this, only not quite as bad.
The basic definition of addiction is to be so invested in a pleasure-seeking activity that it affects your life and the lives of those you love in hurtful ways. How well does that fit your situation?
Your husband is almost certainly an addict (buying addictions are only one of many), and is in deep denial. He is probably buying things to both maintain the denial and get little hits of pleasure chemicals to his brain.
Two suggestions: if your sister or parents will take you in, I would consider that. Your husband MIGHT (not will, but might) be startled out of his denial, at least long enough to reconsider the situation.
But whether he is or not, get yourself educated about codependency and enabling. Join an Alanon group, or look for a group that focuses on using money/spending as a drug. Read books – there are a bunch of good ones. You'll learn a lot about why you are in this situation and what you can do about it. You may learn that your unwillingness to have your daughter live without a father is a form of denial you are practicing, so that you don't have to change.
While at your sister's, do everything you can to be a helpful guest so that your welcome will last longer and you will feel less guilt (another possible sign of codependency). Take advantage of the separation to deal with your feelings, get a job, find your own place.
You could end up living in a car or a shelter with your daughter, and with or without your husband, if you don't deal with these issues. Very hard news to hear, but I have a sister who was the spender (and other unhealthy behaviors), tapped out my family, and very nearly ended up on the street.
My best to you and your daughter. The future can be brighter, but that's not likely to happen unless you make some decisive changes, soon.