Five years ago I suffered from mumps and had swollen testicles. Then for few months I didn't have any ejaculations. I've started producing semen again, but it doesn't seem to be as much as before. Now it has again been several days and I haven't had an ejaculation.
Mumps can damage your ability to make sperm, but it doesn't impact your ability to produce semen. However, any illness will stop your semen production for a while.
A bigger concern is that damaged testicles will also reduce the amount of testosterone in your body. Testosterone is produced by the testicles. If this hormone is reduced, your production of semen will slow down or stop and you will have trouble having erections. There are other less noticeable problems as well.
You need to see a doctor, tell him about your mumps, your symptoms, and ask for a testosterone level check.
That you haven't ejaculated in several days is not a concern. The average male only ejaculates about twice a week, though the range varies a lot.
Thanks a lot.