Do you think I have this?

Hello,

During the winter months I continually feel low, even depressed, to the point that I sometimes get upset and tearful for no reason. Everything seems like so much effort, even just walking up the stairs at home! I'm always tired and have trouble getting out of bed in the mornings. Also, I just cannot be bothered to socialise, and would much rather stay at home in front of the TV where I don't have to make the effort of talking to people. I just feel very run down, often have headaches and am constantly lethargic. My fiancee suggested I may have SAD, and he may be correct, as I feel this way every autumn/winter but don't remember ever feeling like it in the summer months. Last winter I went on a sunbed a few times and I remember it made me feel a bit better, just having the light and warmth on my skin, like it is naturally in summer.

I just wondered if there is anything I can do about SAD. Should I change my diet at all, or start taking a vitamin supplement? I can't really afford a lightbox, and it may be difficult to use one as I work in an office.

Also, is there any point in going to the doctor? I don't want to be mis-diagnosed or given drugs I don't need.

Any advice would be appreciated. Thanks.