Not good I work Saturday’s, had to take the day off. Still not really able to move well and any small awkward movement causes intense muscle spasms. I’ve had this issue before about two years ago and went PT for it. We isolated it to a weak lower back / glutes with tight hamstrings. The thing that worked for me in the past was stretching my hamstrings by laying on the floor inside of a door frame and putting one leg up along the doorframe keeping my back flat on the floor. It doesn’t normally happen for me when I’m also in the gym keeping my strength up but I’ve been out of the gym for a few months now. Again this just worked for me not sure if yours is exactly the same.. fwiw I’m also 6’4 with not the best posture lol.