Hello everybody

After playing tennis with a lot of bending for picking up the balls, a spot in my lower back hurted. when I came home and sat down, pain flamed through my whole leg. Now more than 3 months later I have still left groin pain while sitting. When I am stending up the pain goes away. Also my back en hip gets a bit stiff while sitting for a longer period. Ones I scratched my hip/thigh open during the night while I was a sleep. At first my musscles in my thigh were very tender, but thats gone after a massage. the musscles in my left but are a little bit tender, but no pain. the groin pain is the worst, what could it be?

many thanks