Yeah, you can still train, just dont do anything that causes you to "strain". The belt is also likely a contributor, alot of people wear belts too tight, especially when starting to use one for the first time. It doesnt need to to be extremely tight, you just need to be able to push your stomach into it, its there to give u something to push against not to squeeze the life out of you. That issue youre dealing with is very common, especially when people start to use heavier weights and strain more frequently.
Well I already have an underlying condition... some guy kicked me in the prostate when I was little with his boot with all his power (he was aiming for the butt but hit me right between the legs) and even though we were little I was never the same before... so I have experience "prostate locks" which are scary as you can't believe it unless you experience at least one (you won't want to ever experience another again, EVER). That's why I don't really "squeeze" my anus (aka anal lock) as hard as I can like you're supposed to when you're pushing a heavy weight or jumping because my prostate would possibly lock.
The natural way to do maximal stuff is to lock the gut and the butt to create intra-abdominal pressure and irradiation. I always do (and probably pretty much everyone) that automatically and naturally, but I'm limited ever since that event.
So I think during my 140 kg squat and so on I probably didn't do a good job with that and now...
At least, I hope that's the culprit and not something more serious.