Swamp, sorry for the delay in replying, but hopefully my advice will be of some help.
7 years ago, when I was 18, I suffered from depression. My childhood was shocking, and through the years of growing up, it never showed signs of affecting me. Shorly after my eighteenth birthday, I started getting down. I wasn't enjoying myself if I went out, I was getting moody, snappy, and ad a tendancy to start a fight with any bloke that would even look at me. I hid all this away and did nothing. During this time, I didn't sleep much, I lost my job, and I nearly lost my driving license for wreckless driving.
One night, I was walking home and on my route home, I cross a river bridge. I sat on that bridge for 2 hours, feet over the edge debating wether to just let go or not. For some reason still unknown to me, I pulled myself off the bridge.
It was this that made me realise I had a serious problem. I spoke with my Grandmother, and she said then that the hardest part is admitting you have a problem. From there, I spoke with my GP and so forth. After months of counselling and mild pills, I got myself a job, a girlfriend and things were looking up. I took up a hobby (Lawn bowls - For the relaxing side of it, the walking oudoors and the socialising). To this day, I still have that job, I have trials for Wales in outdoor bowls, and I still have that girl, whom I married 2 weeks ago.
I still get my off days mate. I don't think depression ever really goes away fully and it's a constant battle to not go down that route, but the good things always outwiegh the bad things.
Please, speak with your GP and listen to what they have to say, don't let things lie as they will only become worse. Do keep away from anything with to much caffeine, and stay off the alcohol until you have spoken with your GP. Also, take regular walks to clear your mind.
If you need to talk mate, I'm only a PM away. I'v been there, and I know how your feeling. Don't keep it locked in like I did.