Depression is difficult. This is what I do to jump off that depressive track in my mind. I take a mental vacation from the negative, depressive thoughts. I eat less way less simple carbs and more protein. I act as if this depression were an unwelcome third party and I get mad at it. I verbally out loud talk back to the depressive feelings and tell them they are not welcome and I am not listening anymore and I am going to fight them at every turn and I don't say these things in a weak street puppy way. I get pissed! Anger is good. Anger is POWER IN THIS SITUATION. I go for a very brisk walk or run AS FAST AS I CAN. (If you can't run, punch a pillow).
I talk back to my depression and I laugh at it. I decide what pleasant, positive happy thoughts I want to think and I think them and say them over and over--(I am developing a new thought track)
Fish Oil helps a lot--but exercise helps more. Watch funny shows, avoid sugar, get out in the sunshine (if possible in your part of the country)
Physically do something of service to others.
write down ALL the things you are grateful for as you write them say them outloud:
I love the sunshine
I love spring
Jim Carrey makes me laugh
My husband...
chocolate is Gods gift to humanity

remember, your brain is a computer--you can ignore the old files and create new ones. What we say out loud verbally and put in action with our bodies these are suggestions to our brain (programming) and it will respond by releasing chemicals to support our actions and thoughts. IE if you think or say or act like "the depression is intensifying" then your brain will respond by releasing chemicals to support that.

But if you say think and act "gosh you know I'm going to blow this depression away" then your brain will support that.

meds are great and therapy is great but you have so much power to turn the tide on this.