wow you sound very frustrated....im pretty sure all of us has felt that way at some point.
Im not sure why your weight is going up but i hope this helps.
look closely at what you're eating...i found that i wasnt losing weight because of the few extra biscuits i was eating every day.
im not sure what you are eating each day but the calorie requirements for someone trying to lose 20+kgs is about 1750 or 7325kJ.
to get an indication of what you are eating each day i suggest you go to calorieking.com.au you can list all the foods you're eating and it tallies it up for you. I found it very useful.
The exercise is important...if you're not keen on walking outside in the hot weather...then you have to use your home as a gym or if possible join one (if there is one near you).
At the moment i do exercise videos....(but make sure you have a variety or you will get bored)....i wish i had a treamill....if you can move the treadmill in front of the TV...when an ad break comes on jump on or just walk through the whole show. Or put the treadmill facing a window.
I hope this helps....i understand your frustration...there was a point where i thought to myself that i was never going to lose weight...and after thinking that i ate so much chocolate i was almost sick. I find though that its usually the small things that are stopping you from losing weight.