Can a doctor perform a pap smear against my will or not?

No. A doctor would not perform a pap smear if you refused. That would be battery. However, if you are nervous about having a pap smear, talk to your doctor. She can explain the procedure to you.
Absolutely not. There are many health benefits to having pap smears, the biggest one is looking for early signs of cervical cancer. Catching this cancer early makes treatment easy and very effective. Hopefully you can have a good discussion with your health care provider about the procedure. If you have questions, fears, or any hesitations hopefully they can explain things to you. Forcing you is never an option.