Help!!

So, here's the deal: I am 17 years old. I am about 37 weeks pregnant, and i have decided to give the baby up for adoption. There is, however, a rather massive problem. The father (who is 18), at first, said he was not okay with the adoption, but agreed to a meeting. Then, at the meeting, he said he was willing to do the adoption, and we chose a family. At the next meeting, he said no again, but the meeting with the adoptive family had already been set up. At this meeting he said he thought the adoption was a good idea and was okay with it. Then, two days later, he called me and arranged a meeting with me, where he told me that he had never intended to go through with it and had only said that he was alright with it to be "polite." For a number of reasons, i do not feel at all comfortable with the father being a full time parent. First of all, he has been convicted of several crimes, including multiple charges of misdemeanor theft, bail-jumping and disorderly conduct. Also, i have seen him flip out and throw a bottle of bleach cleaning solution at his mom when she made him angry. I know that even the calmest people can freak out and shake a baby if it won't stop crying, and i just cannot picture myself ever being okay with him parenting full-time. I know that once the adoption is finalized, the parents can deny visitation rights, even if they said otherwise during the pregnancy. But this family has made it abundantly clear that they are fine with and actually want our involvement in the baby's life. I am not sure what his motivation for wanting to keep the baby is. Throughout my pregnancy, he refused to quit smoking pot, cigarettes and drinking (all of which he does, or did, fairly heavily). He said he did not see why he should have to. He has no job, lives in his parents' basement, has no car or license, and somehow thinks that he is going to be a great father. I intend to go to court with him if he refuses the adoption, but i have been told by some that if the involuntary TPR does not go through, he will be given full custody because i "did not want the baby (not true, i just want the baby to have a better life than i alone can give it)". Does anyone have experience with anything even remotely like this? As my due date (February 13th) approaches, i am growing absolutely sick with worry.