Hi Beth,
I'm sorry you're here, but I have to ask the obvious question - why did you stay? How was he able to drag out your hope of intimacy for 25 years?
If you haven't already, read Kel's recent post about not making any changes unless it affects THEM. It's so true and applies to so many situations, gay, straight, male, female, and assholes in general.
I know it's easy to give advice when I'm not in your shoes but....if you can, leave. You deserve more than this. Even if he were asexual he could have at least addressed it with you and tried to work on it. Certainly over 25 years some progress could have been made!! He chose to keep you in the dark and that's cold and mean.