Agony

So thanks to TOM I was awakened by excruciating cramps at about 5:30 this morning.  They are really bad this month, no idea why.  It's funny, before I had kids I NEVER had any kind of period symptoms.  Ever.  I got through C3C+S and BB yesterday, and  I'm supposed to do CA and H&T today.  I have to push through and do it, I have to.  But I'm so tired and I hurt so much it's really going to kill me.  So ladies, tell me, when the cramps are unbearable and you're really fatigued how do you force yourself to do your workouts?  Seriously lacking motivation today, and I have to take my son to a birthday party later which I also don't feel like doing.  I should just pop a Pamprin and quit my bitching, but I just want to curl up in the fetal position on my couch.