I don't say this unless I mean it, but I really DO know how you feel! I started at 274 lbs and my goal is 137...literally half my starting weight!
I live in northern Minnesota where it's winter half the year, so I also share your frustrations about not being able to get outside as much as I'd like to.
I personally count calories and so far this has worked better than other plans I have tried (namely low carb). Though I eat much healthier that I used to, nothing is "off limits" and I'm learning to eat some of the "bad" stuff I love in moderation instead of saying "I can never have X again." This was my downfall...I'd cave in and eat pizza or whatever after being "good" for a few weeks and say screw it, I blew my diet.
I can't walk outside when it's -20 out and I work in a rural area far from a gym, so I have to find exercises to do at home. I have a wii fit, an elliptical machine and some workout videos. So far they have gotten me through the winter pretty well, but I am happy to be able to take a walk outside now that it's getting to be more springlike weather
Anyway...that's my story (so far!) and I'm down over 33 lbs since January 5th. If I can do it, you can too!
What works for me may not necessarily work for you, but no matter what, we're here to support each other and share our experiences. Welcome!