I have a chronic itch inside my left nostril. is there a cream of some kind that i can put in there? olive oil? will that help?

Cortisone: When the itching is severe I would try using some OTC cortisone cream and / or Benedryl cream. When it is calmed down then nasal saline gel may help.

Yes: You can try and over the counter steroid cream like hydrocortisone 1% together with over the counter bacitracin ointment dab on pinky of opposite hand- once or twice a day for several days, inside as far as you can pick inside your nose, This should provide relief for weeks at a time