Sex Life Gone Bust!

I've been with my boyfriend for seven years now, but for past three years I've not been interested in sex at all! And I know it's not him I'm not interested in, because I'm not interested in any one else, even the celebrities... I've tried counciling through the NHS but that's not helped, they tried to convince me it was all his fault! And I know it's not! It's tearing us apart, and beating up his self confidence thinking that it's all his fault. I'm having to force myself to have a sex, and I know that's not right! Help please Agony Aunts