I weigh 310 pounds, my job requires me to sit a lot, about 10 years ago when I drove a long time it did something to where the car and a seat hit your leg on the back side a few inches above the knee. For the last 10 years or so I have been getting terrible cramps in my thigh area, mainly in inner part from the groan to the knee about or sometimes in the front. I scream and can not move my leg an inch. Sometimes it has gone on for 20 minutes and I feel like I could die of a heart attack, like my heart will have a cramp too. It scares me. It seems to happen a lot when I drink alcohol, or sweat a lot. Help.