Aerobic exercise has been linked to reductions in depression. Meditation no need to formalize this or over think it.
When a thought comes just gently allow it to pass and put your focus back on your breath.
How to not be depressed anymore. When i feel lonely or depressed few things make me feel better than reading a good fiction book. You become immersed in the fictional world of a good book and invested in the characters. Here are some suggestions.
But as with social media it is important not to forego real life friends or events for the sake of reading a fictional book. Just sit some where quietly for 10 20 minutes and consciously focus on your breath. Gradually work up to a routine that fits with your needs and enjoyment.
If you have any current medical conditions especially those that affect depression make sure you have regular visits to your doctor. Exercise releases a natural anti depressant chemical in your brain and gets you into doing something active. Start small with a simple walk to the local store or around the block or to your garden gate might be the way to begin.
Walk run hike do anything that gets you moving.