No one in this thread was even attempting to make a diagnosis or guess at the cause of his problems.
I don't care what is wrong with the brain or the tissue, only positives could come from the OP doing some good hip, foot, and ankle mobility work, while avoiding loaded squatting, deloading regularly, and supplementing with a little fish oil and glucosamine. How could that be beneficial?
As far as your suggestions go.. FMS and ART... seriously? The OP is 21 years old, unless his parents are loaded, he's not going to be able to afford that. A full FMS will run at 60-80$ (at least htat's what I charged when I did them) and ART could run as high as 120$ an hour if the guy is any good. Most insurance companies will not cover that and the fact that the OP posted here means that he's looking for free advice.