sudden severe pain near tailbone after waking up

i woke up yesterday and went to get off of the couch, and felt a fairly severe pain right near the base of my spine.  after the initial pain it has continued to hurt. for about 20 minutes any irritation of this pain made me want to cry, and i have a pretty high pain tolerance from having dealt with many dental issues it is not a constant pain, it hurts when i first sit, when i stand up and when i bend over to pick something up off of the floor. also when i bend over to pick something up it almost feels as though there is a bulge at the base of my tailbone. it also hurts when i squeeze my cheeks together and i can feel some not so painful pressure when i urinate.  i am a pretty large guy but am very active at work.  i stock the shelves at walmart and have to carry heavy stuff and bend over all the time.  about 4 years ago i was in a car accident that was fairly severe but was lucky to not have any major injuries, other than a pretty sore mid-left back. i have had no sorts of falls that i can remember recently and also have not had any irregular back pain.  i am gettin ready to ice my back where it hurts right now.  any advice is appreciated