There are a lot of things that can cause a sex drive to dimish, stress, medication, attitude... a lot of things....
check out this thread:
http://www.tfproject.org/tfp/showthread.php?t=104632 it might give you some insight.
Have you also talked to your boyfriend, not in the heat of non-passion, but when you are both relaxed about how you are feeling, and your lack of a sex life is making you feel, without being accusatory, but just saying how you feel...
I was reading an article recently, that summed up the men and porn so beautifully, I figured I will share it here... Men don't look at porn because they expect you to look like or act like or dress like the models, they look at porn because they like to look at other people doing such things...
Did you think that perhaps you picked the wrong moment to spice things up... find out what's going on inhis life...