Wow, I find it really great that people here answer quickly and really seem to care - I've had quite a different experience with similar forums
As regards my depressive episodes, it's kind of complicated. Actually, I'm in some way depressed all the time, I've got the feeling that something is not "flowing" right in my brain, not feeling right. I guess one therapist I once had said this was called "dysthymia" or something like that. However, I still do feel there are different phases, if I wanted to be cynical I might call them bad phases and worse phases

During the worse ones I'm really unable to find pleasure in anything, even things I normally enjoy, it's like I was a bottle with a lot of holes in it - you can fill in what you want, the bottle remains empty eventually. During these phases, I'm tired all the time, have no impetus whatsoever and am just really terrible actually - and I don't really know what helps, except waiting for them to pass. They vary in length, from a few days to few weeks.
At the moment, however, the situation is different again:I seem to cycle really rapidly between moods, including some anxiety and panic (if it gets too bad, I can take my emergency medication, lorazepam, but I try not to take it too often). So this is somehow a bit strange, and may be associated with the loads of strain and pressure I've been under for quite some time now. Hope it will get better bit by bit, and yes, I should meet the doctor - I called a practice earlier this afternoon and they said I could drop by. At the time when I had mustered up my courage however the weather situation looked like this (actually even a lot worse): "£" and not much improvement up to now..
I totally agree with your last sentenvce, this balance is quite hard to find. Sometimes tasks just overtax you and send you spiralling downwards, sometimes they can be some kind of ladder..