I feel for you. It must be very frustrating!

I also write full time but don't have the same frustrations as you. To be honest I'm not sure how I've trained them but the first words out of anyone's mouth are usually something along the lines of "have I interrupted your writing?"

I'd suggest writing in a cafe or at a library or something like that so you're not available when family and friends ring or pop around for a visit. Or you could tell everyone that you're working during specific hours and won't be available i.e. work office hours each day. I know that doesn't always work if edits arrive unexpectedly but it might make your visitors think.

Good luck!