Suggest Treatment For Sprain In The Hamstrings

Hi, am 23 and into Martial Arts from 8 months 3 weeks back while i was stretching my leg fro front to top in air i experienced a jerk like thing in my hamstrings below the buttocks and it was difficult to walk also there was swelling for 2 weeks in lower region there and i couldn't practise much but now after i massage it with mustard oil and use pain relief ointments the swellin has gone but i cudn't move my leg stright up or stretch it ( cant bend down while keeping legs stright) as i feel pain, please help as i want to recover faster n continue my training..