I’m no medical expert but I think 2-3 colds per year is not excessive. You can be lucky and it just so happens your cold falls on your days off/leave.
I was had a summer cold which I recovered from pretty quick except I couldn’t clear pressure from my ears even on the ground. Strangely running seemed to help. My neighbours who work in office style jobs must have thought I was pulling a fast one as I said I was sick then went for a morning run.
I can only talk about the UK but if your on a permanent contract you should get paid lsickness and shouldn’t need unpaid leave to recover from an illness. I’m so far lucky that my pilot manager takes a practical view over blocked ears/colds etc. I think as long as you don’t take the mick like having a sick day every time your favourite football team play you should be okay depending on your employer/manager.
Usually when you are actively flying yourself you don’t notice the pressure unless you are having the start of a cold. Do you have any issues when GA flying when you are in good fitness?