As per description given by you it seems that you have gingival recession which is smthng for which you cannot get a filling done rather it should kept clean by an interdental brush. The important thing is that it should not increase for which you should consult a periodontist. You can see me at medanta between 9-4 or Rohini dental care between 5-8.30

There must be cavity in your teeth if food stucks there. If cavity is small filling can be done, otherwise RCT needed. Visit an endodontist.