Antibiotics do absolutely nothing for cold, flu, stomach illnesses and anything else that is caused by a virus. They only kill bacteria. Bacterial infection is less common than viral infection for a typical adult.
So I think you’re doing things correctly!
For regular illnesses, have some soup, have some honey, whatever makes you feel better and helps you ride out the infection.
If it’s not getting better, if you have consistently high fevers, if there’s unusual pain, if it’s impacting your ability to do normal things like get out of bed—see a doctor.
If the doctor recommends antibiotics, take them. Don’t ask for them.
Note that there are legitimate reasons to get antibiotics sometimes even if you have a viral infection. One example can be a bad ear infection. The reason is you’re protecting against getting a bacterial infection on top of viral. If that happens it could, for example, destroy your hearing. So sometimes they are given preventatively and that’s okay.
Talk to your doctor, and trust your doctor.