Dealing with Muscle Weakness and Fatigue

so, my primary doctor thinks I have some form of muscluar dystrophy. for background, i was very athletic, in basketball, track, and show choir until the age of 15. around that age i started to deal with a lot of fatigue, joint pain, and muscle weakness. my muscles eventually atrophied, and they havent recovered since even with physical therapy. i was diagnosed with fibromyalgia, but I don't feel like that was an accurate diagnosis. i dont relate to most othe the symptopms. i regularly have a low creatine level in bloodwork, so all I can do at this point is wait for a specialist to get back with me. im 22, and whatever is wrong with me is steadily getting worse. has anyone else went through anything similar? i wasnt the strongest kid growing up, but i didnt have many noticeable problems until the age of 15.