There's nothing enlightening about adopting the false nobility of pain as a philosophy. The Romantics already did that and found it to be ultimately unsatisfying.

Your depression is controlling your thinking, pushing you to jump to faulty conclusions. It doesn't matter what you label a positive emotion. There is nothing meaningless, empty, or lesser about living life positively.

Don't succomb to the myth of the suffering artist as a somehow more glorious way to live. Pain isn't the source of creativity, rather it's a substitute for it.