I suffer from bipolar disorder and am worse during the winter. I thought about buying a light box for ages and the price put me off. I ended up purchasing a light bulb that does the same thing through ebay:
http://stores.ebay.co.uk/Vital-Vitality
I am really quite well just now, and I put that down to using high levels of Omega 3 EPA - as advised by my psychiatrist. I get the really pure ones from a company called Healthy and Essential, they are about �19 for a bottle, but as they are of a really high dosage they work out cheaper than the ones bought in the shops.
We all feel depressed at some stage, after a death, loss of a job etc - but true clinical depression is totally and utterly horrendous. Like you when I am well I worry about my next 'episode' of depression (and in my case mania).
I was pensioned off from my job and am doing voluntary work and looking for a part-time job that is not as stressful as my last job (I worked in the Benefits Agency - for 24 yrs and 33 days!)
Good luck whatever you do. Keep a sense of humour, even a twisted one like mine!
Susan