I Have A Cyst Or Something In Line With My

I have a cyst or something in line with my eye tooth in my sinus area between my nose and cheekbone. It has been there for many years and now is bigger. When I put pressure on it I get a sour taste in my mouth and have been having continuous bad breath. It is also above the area that I have a bridge. Had my eye tooth removed 20 years ago. Food does tend to get caught in the bridge because the gum receded. I feels to be pea sized. Thanks. Dan