I felt the same way at your age about having children, and now at 46 I can say I never had children and have no regrets. I married someone who didn't want them either.

In my case, I hate everything to do with hospitals and surgery, so I never pursued sterilization seriously, choosing to be vigilant about contraception. However, I do understand why you'd want to. There are some message boards for childfree people that discuss getting sterilized. You may want to search for them. I have even seen a few recommendations of doctors that have been willing to do a tubal for younger women without children. Some women have been successful. I guess you just have to be persistent.