You sypmtoms seem to be developing after allergy
. Early morning snnezing is also a sign of chronic allergy and some simple things to do over a few weeks would help you.
Avoid dust exposure as much is possible, cover nostrils & mouth when be in a dusty situation.
Try covering you head during night and identify whether morning sneezing
also happens because of temprature variation during night (sleeping directly opposite a fan, extra cool or warm room etc). If so avoid this.
For blacked nose take steam two-three tmes daily.
Start breathing excercises..deep breath..hold..and release slowly.many times daily.
When severe symptoms are there, use over the counter anti-allergic medicines with decongestants.
You can continue with Vit C.
persistent blocking may lead to a sinus infection
so consult a Physician or ENT person if things dont get better.