Why do I always feel unappreciated for the work that I do?

There could be a lot of reasons for that. Some times, it may be because others don't show appreciation for the work that you do, either by downplaying it as "not good" or full on ignoring your efforts.

We all desire some reward. If we encourage each other, that reward can be delivered to others. But then we have to trust that rewards will come to us. The greatest power is the silent hero that makes someone else's life strong with courage or wisdom. This is also the most insecure position a person can take. Loving each other requires trust it will come back to you eventually. What are some ways you work without being rewarded? How many times have you appreciated those around you working? Try randomly complimenting someone. You might even feel better about yourself.