Getting back to original question. Yes, what you are experiencing is common and known. Get very fit - I do mean very very fit - in any sport and the scrotum, possibly the entire phallus retracts into the abdominal cavity. In martial arts this is positively trained, for obvious reasons. The problem arises when the athlete in question is only halfway there, or only beginning to go there. Sudden strong contractions of the strong muscles in the abdominal floor can directly squeeze the testes. It hurts, and it takes considerable time to recover. All you can do is avoid intense efforts until you feel better. Each time I experienced this it was directly and obviously caused by hill sprints.

As should be clear by now from the thread above there are abundant other possibilities. No definitive diagnoses online. The possibility I am pointing to is not something doctors think of. Some coaches are familiar, definitely not all. But if I am right what you are experiencing is completely normal and nothing to worry about. Sounds like you have plenty of worries.

If riding a lot, and doing it intensively as you say, time to ditch the bike from Dick’s.

A badly fitted, randomly equipped commodity bicycle is slightly more likely to provoke the situation than a good bike. But this happens on any bike. Steady aerobic efforts until you feel better. The possibility of these things is always there. Cannot be entirely avoided. Common enough to be known, not likely to occur more than a couple times in a lifetime.