You sound an awful lot like me
I started cycling (properly) in January - my first ride was 10 thigh and bum shattering miles to Padstow and back on the totally flat Camel Trail in Cornwall. It was hideous. Took over and hour each way and I loathed it.
I was also horribly over weight (17 st if i recall) and started Weight Watchers at the same time as the awful bike ride.
I am now 8 months down the road; I have lost 4 stone, and can happily ride 30-40 miles with only a little bit of bum ache. I still struggle with hills - some of the hills in Devon are mountains though, so I don't feel in the slightest bit bad at getting off at walking up them sometimes.
I have started riding to work as well - the way to work is 7 miles downhill which is great - but the way home is a bit of a killer. Why can't we take bikes on buses huh!
I found that if I was going on a longish bike ride, then a jacket potato, some chicken and salad is good lunch fuel. I always have either crumpets or shredded wheat for brekkie if I am riding to work. All pretty good on WW - I don't know how it stacks up on SW though... and a banana. Bananas are magic
I think what I am saying is you're doing really well - keep at it; it gets easier and easier, and more and more addictive.
Well done and thanks for the amusing thread (which I have read in one go this evening) x