What Could Cause My Left Testicle To Droop, Have Pain When Touched, And Develop A Hard Spot Near The Bottom?

Hello I am 18 years old and I started to notice that my left testicle was drooping lower than my right and after a few more days from that incident my left testicle started to hurt not like achingly but whenever I moved and the testicle would hit part of my underwear. Its been 4 days now since I first noticed the droop and pain and my left testicle seems to not hurt as much as it did before when I moved and I can move a bit more freely now. But the left testicle is still drooping and I now feel something hard I think near the bottom and towards the back of my left testicle where it hurts when I touch it and that seems to be where the main pain is coming from.