Had vericocele surgery. had low soreness on right testicle since (1 yr) told it was because of lack of support from boxers- i've always worn before?

Few things possible: Pain directly in the testicle could be from testicular atrophy, a consequence of having the varicocele or from how the nerves healed. Also, hydroceles after varicocele surgery do occur and can cause some vague pain. Infection is also possible sudden pain is a true emergency. An exam & repeat sonogram is a good idea to investigate the cause.