First you have to have lawyers involved, for your protection, and your daughters. It doesn't have to be ugly and it can be expensive if he chooses to fight, but to be protected that is the best way. It isn't fun but her father is very much responsible for her quality of life and well being. Why should you have to struggle?
If you want to hope he will come around and just follow a verbal agreement you can end up very frustrated. It isn't mean just getting it in writing nor does it have to be a battle, just explain to him this stuff needs to get worked out and on paper so everyone is clear. You can go through mediation which is a LOT LESS expensive but you both have to be able to sit down and agree to things. Being her father he may realize how expensive daily life is with a child and work with you not against you. If you have it in writing then at all times you know where he has to be held accountable. Family law will iron out child support and visitation and they do it for the child, not the parents.
If he doesn't have a job, a lawyer will give him a set amount of time to get gainfully employed at that time he will take your income and her dad's income and the montly expenses and figure it up what if fair. You can get scholarships for preschool if you qualify (in Colorado they have to be four I believe). Same with most daycare systems, call your city and state offices. That way you can go back to work fulltime if you qualify for fulltime daycare. I know you probably don't want her to be in daycare all day, I totally understand that.
I know it is hard, believe me I am trying to raise two kids and have WAY too large of a mtg payment not to mention I know how expensive daycare is. I don't qualify yet because my ex makes too much money and our settlement with marital support, hence he had to really step up and pay me until my son got to Kindergarten next year. Now I will be able to go back to work fulltime in the fall.
Hugs!
Most states have child support calculators too, look it up under family law. That way you can determine what the state will on what is fair.