What to do about the depression associated with marijuana withdrawal

I am 25 years old, and for about 5 years I have been smoking marijuana every day. At first I think I did because everybody else around me had been smoking and leading productive lives, so whats the harm right? I started out the same way everybody else starts, a hit here, a hit there. I did not realize that I was addicted until I no longer could do anything without being high. Recently I decided to quit and achieve that level of sobriety that I once enjoyed. Easier said than done ! I think I was not being realistic, because rather than quit gradually I quit cold turkey. I was up to about an ounce every two days. When I quit I started smoking more cigarettes, and then got the bright idea to stop smoking those without tapering as well. Now I am extremely depressed, and don't seem to see an end to my depression. :-( I took the advice of one of the posts and got Valerian Root and that helped a lot with my insomnia. I would appreciate any advice on how long the depression might last, and what natural remedies might be helpful. Not really into prescription medications, but if that's what it will take than why not. But only as a last resort.