U just need to visit a Periodontist(Specialist in Gum related issues)who can assess ur condition and do the proper treatment. Such condition has occured due to improper brushing technique or improper oral hygiene maintainance A minor surgical intervention might be required which would improve ur gum condition
Next Steps
Before the tooth faals off by its own pay a visit to a Dentist.
Health Tips
Try not to bite forcefully on the teeth which would further worsen the condition.