I understand the position you are in, I am a young single mother with a deadbeat ex as well. The best you can hope for with regards to the father, is that if he doesn't want to be involved that you at least get child support (life is really rocky raising a kid without any support from the ex).
As far as feeling like you will be alone forever, I understand the feeling. I get that way sometimes too. I also see that I am doing what's best for my son by focusing on him and making a life for us, where I do not need a man for anything but companionship (and of course sex
I don't have many opportunities for meeting people, even though I am going to college, because I can't live the college life to make lasting friendships or relationships. The thing I've found is that you work on building solid friendships with people who care and hopefully can understand that your life is hectic. In getting solid friendships, you have the support you need and you will meet other wonderful people through them (and hopefully Mr. Right someday).
Having a son myself, I see issues come up because he doesn't have a solid father figure in his life. I have tried to keep his relationships with male family members and guy friends of mine good, so that at least he has positive male role models in place of it (though that never solves all the problems it helps).
I do agree with others, that having the wrong man that may end up being a bad influence on your child (and possibly on you at some point) is worse than being alone. I watched my mom be a single mother and cycle through men, only leaving one when things were bad with one and another came along. There are a lot of issues between her and my brother and I because of her bad choices in men. She is on husband #3 now, and he is a complete ass to all of her family - but in her mind at least she isn't alone. It has caused her to become alienated from a lot of our family, and esp. from my son and her other grandkids as a result.
My advice is when you meet someone, try becoming friends with him first and get to know him and how he feels about kids. Be honest with the guy, take things slow, and watch for any negative signs.
Hopefully some of this helped, and good luck