Since I was like 12 I was blessed with the genetics of an 80 yo. Having muscle spasms, hernias, and all sorts of bizarre crap. The two times in my life I got into a workout regime things would get progressively better until months down the line, when I'd have to do surgery of some kind, likely because I 'worked out too much'. Doctors tell me to start lifting weights, but they don't seem to believe me and simply tell me I'm a male and young and shouldn't be as frail as I am. No tests in 20+ years have shown anything out of the ordinary, except for whatever problem I developed all of a sudden, so it's no wonder. I'm afraid that trainers in a gym wouldn't be any better. Got no idea where to start. Pool workouts with the elderly maybe?
The other comments here are really good, if you have ruled out actual conditions you might just have a body built on a Friday afternoon. My go to exercise goals are always
#1 Continue to exercise , all other goals are in pursuit of this goal.
#2 Do exercise you enjoy. Find what you actually have fun doing and do that. If you hate what you're doing it will only make it harder to continue to exercise. There are a million types of exercise and they are all fine. If you get bored switch it up.
#3 Do not injure yourself. This will prevent you from continuing to exercise, which is goal #1. If you are hurting yourself doing conventional weight lifting, then stop doing that.
#4 Any exercise is better than none, there is no such thing as functional training unless you are a professional athlete, or have a very physical job. Walking, swimming, running, weights, calisthenics are all fine. Every type and variety of exercise is fine.
Good luck comrade, your body will thank you.