most men are born with one testicle larger--usually the left one.there are many types and causes for orchitis.keep notes about it.i use my calendar book to note times,situations,factors, what hurts(is it the normal lumps from the cord inside that hurt?) and what helps(reclining,supporters,icepacks--very useful when you have permanent epidydimitis,as i do)different sex positions and activities can help substantially,even if the pain never goes away,or shifts location,there are always things that you can do.just remember,if you use ice packs your motility/fertility can skyrocket ,this effects family planning.    definitely see a urologist.DO NOT HAVE SURGERY without second and third opinions with doctors you clearly trust.inexperienced surgeons can easily cause a lifetime of intractable,debilitating chronic pain,like the kind torture victims get,where suicide becomes a reasonable treatment option(in your mind)  be careful  good luck