What do I do, at my end?

O.k., up until this point I've had pretty clear thought on all of this, but this morning was the last straw. My children's father and I split up back in May, right after I found out I was pregnant with a very unplanned pregnancy, this will make our 3rd baby together. The problem then is the same now, he can't stay straight. At 30 yrs. old he dosen't seem to know that your children always come first. I told him if I was going to have another baby, it wasn't going to be him. I was no longer going to work to support him. Once we split up I asked him for only 25$ a week in child support, he refused, said he couldn't afford it. I let it go trying to keep peace, because to me the most important thing is he keeps a relationship with his boys. Still, for the last 6 months it's been a constant struggle. He calls and says he'll be here to get them- dosen't come. He dosen't even call for weeks at a time. (we live in a 3 stoplight town, so he's never far away). It's killing my 6 yr. old. He crys to the point he makes hisself sick. Anyway yesterday he called to see if he could have the boys today, I of course said yes! Then I asked if he knew what today is, he said no. Today is his sons Birthday and he couldn't even remember it! Blamed it on a cold makeing his head foggy. Here it is 10 o'clock and he just called to say that he wouldn't be here till 3:00. Said he has to go rake leaves, Did I mention that the wind is blowing at a steady 40 m.p.h.? I mean W.T.F.? I'm taking him to court for Primary Cust. and Child Support. Mostly because I want him to know his behavior is not o.k., and should something happen to me, I do not want my children to live with him. Visitation is o.k., but it scares me to think he would be taking care of them. O.k. so sorry this isn't much of a question, as a rant. And I'm sorry for that, but it's breaking my boys heart is breaking mine! Do you have any expriences like this? Any advice? Help!!!!