There's always a lag time between accomplishment and external validation. Sometimes it's brief, but more often it's not. In my own case I'm used to it being on the order of two years or so. ;)
My recommendation is to learn to be satisfied with the results when you have created them. Be your own first judge, and if you feel you've done a good job on something from as objective a viewpoint as you can get, enjoy that. Reward yourself somehow, and take someone else along who'll at least lend a sympathetic ear and share your enthusiasm. Get yourself a nice dinner out, buy that expensive book you've been wanting, whatever.
Then plunge back in and do some more, while you still feel good.