One of the problems with depression is that it feeds on itself. When you depressed you don't want to do anything and that, in turn, makes you even more depressed.
Could you start exercising? Nothing strenuous, a regular walk, or go for a swim, or a cycle ride. Maybe check with the CAB if there are any self-help groups in your area.
You should see your doctor. If the depression is severe they could give you medication that will help you.
Good luck.