Hi ! From your history, it seems that you have got a persisting
epididymo-orchitis which is giving you trouble. I would suggest you to go for a proper scrotal support without which sometimes unnoticed trivial repeated trauma gives rise to recurrent inflammation of the testis and
epididymis. The pain of the testis is referred to the abdomen due to its nerve supply being from T 10, level of the
nerve root from which it derives its nerve supply. This may also give rise to nauseating sensation which you got. You should not stand for a long time, and take proper rest.
You can discuss with your doctor for a urine and semen culture sensitivity test to rule out any infectious pathology, as routine urine test may not show an infection and also proper antibiotics can be judged by a culture sensitivity test. Also go for an absolute
eosinophil count which might suggest a microfilarial infection if you are from an endemic area where it is prevalent, for which your doctor can prescribe medicines for you. He may also advise you for Doppler
ultrasound of testes if need be.
The pea sized lump on the top of your epididymis may be a
cyst of the epididymis which could arise after
vasectomy due to retention of semen or it might be from the beginning which have come to your notice now due to the inflammation of the same causing pain along with the present inflammation of the testis and epididymis.
You have to discuss with your family physician on all these aspects before starting any treatment. Wishing you an early recovery.