One thing I used to do when I was working and probably need more now, is to save thank you notes, print out those emails of appreciation or acknowledgement of accomplishments and put them in a book or large envelope or box. When you feel that you're not accomplishing enough, or really dark days like I sometimes have when I question my current or future value, take that box out and remind yourself that you are of value and accomplish goals. Even small ones add up.
I'm also a list maker. It focuses me and when I mark something off I can see an accomplishment.