Appreciate all of the responses everyone.
I'm seeing someone again for therapy on Monday.
I was prescribed citalopram and only took one tablet on Tuesday morning. I had bad side effects such as massive drowsiness, teeth grinding, a worsening of tinnitus and, the one that made me not take another, really bad insomnia including not being able to sleep at all the first night and very poor sleep since. Granted, these take a while to get through the initial side effects, but insomnia is something I cannot do for even a short period and if I am to be totally honest with myself, I am not really sure I meet the clinical "threshold" for anti-depressants. It seems that when I get really down that it's situational and temporary. I do definitely have anxiety issues - general and particularly around socialising and sleeping - exacerbated by and quite possibly caused by alcohol - although the social anxiety goes way back to childhood - and something I just thought some people were pre-disposed to - but clearly I now see it can and should be addressed / improved.
So, I think I am going to forget the meds. I would be lying if I said I wasn't thinking clearly - yes, negatively, and head a bit all over the place post withdrawal, but I am not sure I am veiled in such a depression that it would hamper any progress made in therapy. I also need to consider that sometimes down periods just happen, and it has been grey, windy, rainy, damp and cold for about a month solid here in London. It definitely has an effect.
I would love to take some time off to deal with all of this stuff in a vacuum - and be able to afford to go to therapy more than once a week. One 50 minute session is so far short of scratching the surface. But, sadly, life must go on!