What Causes Swelling Of Scrotum With Lump?

My right scrotum is swollen and has a lump forming on the right side of it.The swelling started app. 5 yrs ago, i am not experiencing any pain at all,but i thought this was a result of having sex while using a cock ring,which is usually removed before orgasm,but this particular event it was left on, and i felt something weird like fluid entering the scrotum.How serious can this really be,could it be fixed or am i going to have