Teahouse - I started the C25K a couple of years ago and was horrified to find that I couldn't even manage the first day! I could only manage 4 of the 1 minute runs 
But, the next time I went out (two days later, as per plan) I did manage it. Unfortunately I also pulled a muscle, so that was that for a while.
But I started it again this year - after having spent a year training in the gym to get fit - and it has been amazing.
I really never thought:
a) I would be out running in the rain, cold and/or snow!
b) I would be running 4K within 6 weeks of starting
The programme really does help you make great progress (injuries to one side!). I remember very well thinking I'd never make it beyond 5 minutes, and the jump beyond that seemed ridiculous! But you can do it.
Someone on one of the running threads talked about it being in your mind, and I would definitely agree with that.
Re the cold - I hate the cold and also have Raynauds, so I sympathise. When it's really cold, I wear:
- long running tights and over the top, track-suit bottoms
- thermal, long-sleeved t-shirt, short-sleeved running t-shirt over the top, lightweight running jacket over the top of that
- hat
- running gloves
Yesterday I also added a snood round my neck, to pull over the bottom half of my face and found some hand warmers which I put into my gloves.
The problem that you have when you're starting out is that you're just not running for long enough to really get warm. Once you reach the longer runs this will help you more.