Have you tried CBD? Or even a little bit of indica, the “downer” strain of weed might help. Not too much, because that could lead to weed shakes 😅

I've heard magnesium helps since it "calms" muscles. I take magnesium citrate gummies each night and I feel it helps - may be worth a try

Magnesium should help like pp said. You can also do some light stretching. You can look for a low impact cool down on YouTube. When your muscle spasms try to wiggle it. IE if your calf cramps pull your toes back and then point them a few times. It hurts but it interrupts the clenching. Most people freeze and tense up which makes it worse.