Hello
You are 25 years of age so unlikely to have a genetic immune deficiency at this stage. You are more likely to have
vitamin deficiencies like vit D deficiency which makes you more prone for repeated infections.
You are also unlikely to have chronic illnesses like
diabetes as you have got yourself checked so many times.
Next Steps
you should get your
Vitamin D levels checked and also try to get other vitamin levels as well. please have a rethink on your dietary habits and find if you are having lots of unhealthy food or are traveling via a media where you are exposed to lot of other people which can transmit infection to you.
You can start a broad daiky multivitamin like Tab A to Z once a day to build up on your immunity. once evaluated specific cause can be found and treated.