TBH BWB if he is that upset I would bloody sod the doctors. I have a history of depression too.
DS2 went through a really bad patch with cold, after cold, after, cold. The GP just keep fobbing me off, he then was really unwell was evening so called the out of hours people and he ended up in the hospital on really strong Anti B's as he had a shadow on his lung, due to the inpacted infection. I was so pissed off I moved GP's.
He is your son and you know best. Tips for the nose though, salt water in a syringe to clear it, Medised as tort said and also raising the bed or giving him a pillow. Steam can also help we have a humidifyer for both boys now.
Feel free to worry about him to me, it is natural you are his mummy