uncomfortable pressure on my uterus, back pain and much more

Tristan
It's near the end of my period and it was lighter than normal at the beginning of my period, but now it's heavier than I havever had and I naturally have very heavy periods but I'm feeling a very uncomfortable pressure along my pelvis area and pubic bone area, back pain, slightly nauseous, huge** blood clots I've never had in my life, and I had periods for 9 years, very excessive bloating, makes me look like
I gained 20 lbs over night. 
Everything hurts, hurts to move, to stand, to sit, etc. very constipated. Everything hurts. I don't know what to do. Should I call my gyn?? Should I wait until my period stops? (If it does before my trip to Florida which is in two days) should I go to the ER?? Am I just being over dramatic?? Help!