A.. Its sounds like you are suffering with periodontal disease. This is primarily caused by plaque build up under the gums. This plaque contains bacteria some of which can cause the bone that supports your teeth to decrease in strength and amount. The bone is the foundations / support for your teeth. Periodontal disease affects a large amount of the population to some degree and there are certain factors which increase its effect , these are smoking, diabetes and a possible genetic factor (have mum and dad lost a lot of teeth ?). I would advise you to have a full consultation and x-rays to assess your bone loss and then look at possible treatments which include seeing a periodontist , a dental hygienist or looking at dental implants to replace missing teeth.

I hope this helps you.