Fear and/or tension will make the pain much worse. Try your best to relax, and go SLOWLY! Communicate carefully with your DH, so that he understands your fears and discomfort, and so that he knows you're not rejecting him, and that he's not doing everything wrong! Try different positions, plenty of lube, a little pain medication before, and I've heard many recommend a glass or two of wine (don't get carried away - not good for baby) just to help you relax.
By the way - look at how many people have more than one baby. It'll get better. Be sure to talk to your OB though if things don't seem to improve. He/she might be able to help.
All the best!