What happens when I violate my unsupervised probation three times and I don't have enough money for a lawyer?

I was placed on unsupervised probation when I was 17 for a possession charge in st louis, mo. Now I'm 18, and about a month ago I was charged with possession (weed) and paraphernalia (scale). A couple weeks later I was pulled over and charged with paraphernalia (pipe). I have no money for a lawyer, and my first court date is tonight. Not to mention I doubt I'll have money for a lawyer on the next court date as well. What should I do and what can I expect, please and thank you :D