Gums tingling for 9 months and has turned greyish colour where it hurts... Cause?

Past dental work? If you had past dental surgery such as removal of your wisdom teeth, sometimes nerves arteries or veins can be damaged. If blood supply to the area is compromised the gum tissue can die (turn gray) and tingling can be temporary or permanent. I would seek out an oral surgery consult to determine the cause.
Grey gum disease. This is a serious health issue, with symptoms that can include bleeding gums, itching pain, and a bad breath. The condition also called acute necrotizing ulcerative gingivitis and visit to a dentist or periodontist is warranted.
Blood Supply. Your gums should not tingle or turn gray and certainly not for 9 months. The loss of color is suggestive of either a significant anemia or problem with the blood supply. You should see your physician to be sure there is no medical reason for the findings you describe and if not you should see your dentist. You should do this now and not wait any longer for evaluation and diagnosis.
Need eval. Can't tell what's going on without examining you. What are you waiting for? 9 months of symptoms are messages from your body that you need professional care. See your Dentist or preferably a Periodontist (gum specialist) ASAP. Don't wait, call now.
Blood Flow. Decreased blood flow in the area may be damaging the tissue. This should have been addressed 9 months ago. Please call a dentist or oral surgeon for an appointment.
Not normal. Not normal See oral surgeon ASAP for exam/xrays/recommendations.
Could be serious. Need to see a dentist. It may be ANUG (acute necrotizing ulcerative gingivits) If it is, it needs professional treatment.
Attention needed. you need to see a dentist ASAP as gums turn grayish after accumulation of pulque that in turn change to calculus ( tartar) if not cleaned daily by brushing and flossing and periodically through your dentist every six month to be exact not nine So attention ISPs needed..
See dentist first. See your dentist, Perhaps the gray color is calculus shining through and you need an excellent cleaning.to remove all supra and subgingival calculus. This is the most conservative and likely cause at age 21. If the dentist finds that all is ok, you may be referred to your MD for a complete workup.
Contact your dentist. it is very difficult to give opinion without complete exam. Please consult periodontist. Or dentist. Good luck. There can be infection, gum disease, exposed roots, traumatic bite. Many causes and many solutions.
Possible abscess. could be a tooth going bad, possible abscess, or other dental malady. See a dentist as soon as possible to diagnose and treat this problem before it gets worse and does more damage to your health.
See a dentist. asap. This needs immediate treatment to prevent further damage to teeth, gums, bone.
A gum infection. The gum color should be pink or s lightly red. If gray then there is a problem with your gums. The gums may be infected and beginning to break down Have a periodontist look at it. .