90% of
@EasMid's post applies to me. Mine is probably more a poor assembly/design issue than a damage-related affair, though.
I've suffered since my early teens. Everybody's situation will be different, but you should, with care, be able to experiment and find procedures that (at least) help. Or just find the things that you shouldn't do.
Standing still is a real problem for me, just a few minutes is too much, but I can potter about all day. I also am not a fan of masking the issue and generally avoid that path - I also don't keep embrocation tubes in the bathroom, having accidentally attempted to clean my teeth with Deep Heat once,
If your situation is usually one-sided, that can give clues. Car seats can be a bit slouchy and driving one handed produces a long-term asymmetry in muscle usage - as does the use of shoulder bags, often always carried on the same shoulder. Etc.
I'm either getting better at containing it or it's getting better on its own - who knows...
I did also try a TENS machine, with no discernible benefit, but others do report good results.
I do find that a hot bath is beneficial.
It is always possible that an osteopath or chiropractor
might be able to help - I sorted out my grumbling knee after two decades by smashing it off the road near Seighford, having fallen off a motorbike - it has been virtually no trouble in the two decades since.
You may just need to experiment and see what seems to work in your favour and what seems not to...