hi, im 17 years old. i have noticed that i have a lump on the bottom back of my left testical. i can only feel the lump when i have an erection,and when i have an erection the lump feels hard, and ever since the lump showed up i have been having weak ejaculations, i feel like it might be physically blocking the semen . when i am not erect the lump disappears, i cant feel it at all.
does anyone have any idea what this might be?