What Can Be The Reason For A Painful Knot Like Swelling Over My Right Testicle ?

sir I am a male 21 years. I have a problem with my right testicle. It started about 5 years back. actually I used to play football by making balance with one feet and playing by right feet only to hold the ball in air for longer time, so after some time due to continuous contraction and relaxation of muscles of lower abdominal part and abdomen -foot joint, it started little swelling and pain around that area. finally i left playing and pain also became normal. Last year i started going for horse riding and it again started paining heavily along with a kind of knot over my right testicle (that knot is still there and whenever i press it it s really painful and it seems that the knot is still growing bigger) and sometimes it used to swell also very badly along with serve pain. I left going for horse riding but pain is still persisting sometimes along with swelling. Last year i consulted a surgeon and had also gone ultrasound but there were no symptoms of hernia and he said you are perfectly alright but I know something is wrong with me.