So sorry to hear about the decline - I have go so so many rejection emails! Just don't take it personally and stay motivated!
How good are the reviewers' comments? If you think they sound good - maybe, you should try to resubmit the application by May! Although it is touch and you would be exhausted after the comps - but there are still three days and a prospect of getting the grant next Fall! The more you try, the bigger your chances!