It sounds like you tweaked/pulled/strained your hip flexor. I would say stretch it a few times a day, R.I.C.E., and take a week off freestyle and soccer to see how its healed up. I am not a doctor though, if it persists even after you take a few days break, then you should see your doctor.
I've injured both hip flexors numerous times from both freestyle and regular soccer :thumbsup: