How long have you had your snake.
Is it CB or WC.
I was in a similar situation with a WC last year, it eventually started feeding after 15 weeks.
I had tried everything I could.
I was at the point where I thought that I would have to force feed (a last resort) then to my amazement she took the mouse straight out of my fingers, coiled and then swallowed it.
She has fed reguarly ever since.
I think the best advice is from Philippe de Vosjoli (author of The Ball Python Manual) Don't Panic !