After stretching, I could not stand from serious hip pain and burning. I have leg weakness and muscle spasms. Want to get back to the gym, but pain?

RICE. Rest, ice to affected area, elevation if able and anti-inflammatory (if no reason not to take one) are initial treatments. Your complaints of weakness of leg are concern. If no better in next 3-5 days, please see your doctor for evaluation. Best of luck with this. Dr R.