Hello Muhsin
You yourself know the cause of your bad conditioned tooth.
So firstly I would recommend you to stop smoking... Or atleast reduce
Secondly donot panic. Theres still hope to save on hereafter.
The loss that has already happened should be eliminated
The tooth's that have the bottom section only remaining.... Get them removed.
The broken tooth's can be examined and planned if a root canal treatment can help.
Go for a round of scaling once the above treatment is performed
Next Steps
visit a dentist as soon as possible
Health Tips
smoking is just burning money...
go for a counselling and try your best to save yourself from smoking.
what is already gone is gone...hereafter try not to repeat.
take care