Eat a banana or a chocolate bar, then go cycling or walking if you can bring yourself to do it go to swim.
Running twice a week would do just as much as antidepressants pills! You have to get over the three week hurdle, but then .. you almost do it for fun!
Every day three omega-3 capsules and every day 10 km. cycling on your home trainer. Success is guaranteed.
If you have blood thinners; careful with St John's wort. Tip of the pharmacy
Buy a notebook and write what actually is given a sufficient. It's a trick that worked well for me and also without side effects!