Welcome in H.C.M.
I have gone through your query regarding painful sore in your one nostril
and painful ulcers in mouth as well there is headache and pain behind the eyes.
Here I would like to tell you don't touch your scab in nose as this part of face is danger area and manual manipulation may spread in infection internally up to cavernous sinus
, which becomes an emergency.
For immediate relief you should take-
1- Tab Paracetamol
2- Antibiotic ( Broad spectrum )
3- Boroglycerine locally in mouth cavity over mouth ulcers.
4- Antiseptic ointment to nostril over scab.
I hope this will help you.