i also had a left sided issue, i actually had bilater sh but the left side is what hurt first, and much worse. preceding it was a series of injuries on teh left- first the foot, then the knee (twice). i think that those injuries lead to imbalance which in turn cause the sports hernia(s).
the testicle pain is very common. the pelvic pain is also common. tailbone, perineum, root of penis, etc, can all be affected by this injury and the changes this injury causes to the muscles. compensatory patterns cause pain and they are painful during the process of reorganization.
joe is dead on about working your core but do it slowly and be mindful of how you do it. take your time overall. stretching too deeply can also cause more irritation and lead to more problems. that happened to me pre-op and post-op; deep lunge/spoas stretches may feel good but also stretch the nerve(s) that is irritated in teh injury so be careful with it. my pt, pre-op, had me doing way deep stretches. i was wondering why it always hurt afterwards, now i know. i only made my recovery harder.
a rolfer is a very good idea but give it time before going to see one. i waited 6 or 7 months. go see the best manual therapist you can, they can help. a rolfer may not be able to prescribe a pt protocol for you unless he/she is also a pt. any pt who claims to use "rolfing techniques" is not a rolfer, and that woudl be a bogus claim and i would seek out a certified rolfer.
he or she can help you with those imbalances.
yoga will be really good for you postop but don't go for gold, take it slow.
same with pilates, it helped me some but also made my hamstring worse. the instructor must be aware of the condition of your core and hwo sensitive it is at the time of treatment. flareups can happen easily, as you have read here, so take it slowly.
it's been a year and a half post-op for me so far and things are improving but really slowly. i am not considered a failure, however, but one of those people who was totally wounded and dyfunctional by the time i had gotten a diagnosis. so it will take time to get back to "normal." it sucks but this is the reality of this injury if you get it pretty badly and go a long time without proper help.