right testicle oversized and mishaped

my right testicle has been screwing with me for some time and it can just not be ignored anymore. it feels like it is almost too big for its sack. is mishaped and isn't so much is painful but is discomfertable. this has been doing this for about a yr now and have been to the doctors a few times but is still the same. have had std tests and no infections. more recently when i ejaculate it feels as if that testicle is not ejaculating and almost tightens up. there is a clear discharge throughout which has always concerned me but the tests have said i am clean. even more recently when i ejaculate and it feels as if the one doesnt ejaculate, but if i or my gf keeps going i have a second orgasm with none if little discharge and a release in pressure from the right testicle which usually tightens up after ejactulation. i wasnt as concerned b4 because everything was still working properly but now i am stumped and my doctor has offered me no help?