Pain in medial posterior of left knee

Male:21:168lb

I have developed a pain in the medial posterior of my right knee. The first instance of the pain occured in the final few miles of a 34 mile cycle run when I felt a twinge of pain in the above mentioned area. I normally cycle around 120miles a week in about 3-4 sessions and haven’t been troubled with pain in the past. However I had recently adjusted my riding position and think I might have had the saddle a little to high on this occasion, something that I have since corrected.
The pain appears to originate from the point where one of the tendons coming from my hamstring goes behind the knee and into the top of the tibia. I assume I have damaged the insertion point of the tendon.
Has anyone else had an injury similar to this and if so do they have any rehabilitation tips? The injury seems to bother me most when climbing stairs and I get the impression that it isn’t getting the chance to heal as it is put under strain when I walk.