Sorry but you can't combine an annual pass rate with the dining plan or MYW tickets. Annual pass rates can only be used for room only reservations. Once you add the tickets you've become a package and the annual pass rate can't be applied.
Since the only way to get the dining plan is with a package you might be better with just staying with what you have. But you can consider getting an annual pass, swapping over to a room only reservation and buying the Disney Dining Experience-DDE card which will give you 20% off on alot of dining.. It might work out for you better in the long run or it might not. You'll have to juggle the numbers and see.