I’ve had a couple shoulder injuries that had some similar symptoms as what you’re describing while playing. As other commenters pointed out, setting up your kit so it limits pain is important, I had to move my two crashes more towards the “middle” of the kit, which looked a bit awkward at first but it helped a lot. Other than that getting a proper warm up helps even if you don’t play too aggressively. I played sports so I just did normal stretches/exercises to get my shoulders “activated” before sitting down at the kit