Discomfort in right testicle. Serious?

3 years back, I had an erection. That time there was a feeling of strain. From then, sometimes I feel a discomfort in my right testicle with slight feeling of strain/discomfort/heaviness in right lower abdomen. Also I feel a little pain/stiffness/uneasiness in my lower back. In 2018, at the time of occurrence, I had undergone USG. USG report was normal. Also, while visiting one surgeon in 2019, for consultation on some other issues, I had my testicles checked by the doctor. He inspected by his hands and told me that the both testicles were equal in size and were properly in sack. The the problem has not gone away. I also have not seen any doctor on the issue since then as it feels very embarrassing to discuss the same on face to face with a doctor. Please suggest me what to do. Is there anything serious?