Hi Mogeii. I know what you mean. During depressions you have ups and downs, and during the down period you see life in a different light. It's depression playing nasty trick with you.

What really worked for me was doing exercise (a lot) and reading self-help books.

Especially goal-setting (mostly small goals) and visualization exercises and changing my self-talk worked really well to overcome depression.

Perhaps give them a try. They changed my life for the better. Don't give up fighting your depression; life can get better.