Deniz,
Medication can help. It really can.
For me, however, I've not used medication for more than just a few months. It takes my ambition and flushes it down the toilet.
To fight my down times, I try do do something different or fun. I also take on new projects in work and play and pour myself into them. I like to do something that someone else might deem impossible. For example, a few years ago, I decided to build some telescopes. I had to learn metal work, fiberglass, optics, woodworking, CAD, motor control of telescoopes, and all sorts of other things. I did it and produced some of the finest large telescopes in the world. I'm very proud of that. I also learned to hang glide. I took up backpacking and hiked the trails all along the Sierra Nevada.
Exercise also helps reduce depression.
Good luck hon. It's a real bear to fight depression and it ain't fun. I still struggle with it.
Cindi