Need Help with Gnats PLEASE

I am not sure WHAT forum to post this on, but since this has "clean" in it, I chose it.... if you know of a better location- -suggestions are appreciated.

I have an "gnat" infestion at my house and I have tried everything to get rid of it. sometimes in the past when a banana peel or whatever was left in the trash or compost bucket small gnats would appear, but as soon as the item (banana peel, apple peel) was removed the gnats would disappear.

For the past two weeks I have had small gnats swarming around my kitchen sink and i have tried everything I can think of to get rid of them. The majority seem to land on my window above the sink. I have tried cleaning and cleaning and cleaning..... and I have even sprayed flying insect killer and spider killer on my window. That seemed to make a dent in them, but I can not seem to get rid of them. They are too small to eliminate each one by hand..... and are hard to hit with sprays as well without just spraying the entire area.....

I have scrubbed, put out vinegar to try to run them off, put out water in containers to try to attract them to it to drown them,.....put small amount of cooking oil in a container trying the same approach and NOTHING is working!! They are driving me crazy and I don't know what else to try.................. I have never had this problem, and never heard of anyone else having it, but I would sure appreciate any suggestions that you think might get rid of them for good!

Thanks!