Hi Kelly, its never too late to start improving your health. I've been down the same road - thought I could never change my bad habits but I did and I've lost 34 Lbs. in 6 months and I'm very near my goal of 135 now. I also went from a 42-inch waist to a 31-inch waist.
You too can reach your goals! As others here have said, start by walking a bit each day, 30 minutes or so. Progress to walking a bit faster when you feel that you are able. I usually just grab my mp3 player and go for it.
There are also many exercises which you can do at home, all free. You can do ab crunches, lunges, mountain climbers, jump rope, jumping jacks, squats, planks, and others. These are the same exercises which are offered in many fitness classes and you can do them at home too. Videos help but you can do it pretty good with just good music.
Next, I recommend that you get or get access to an accurate scale. You need a way to track your progress.
As to cutting out soda etc., I'm convinced that if I did it, then anyone can. I was a big, big rootbeer/pepsi fan. And in those days I was known for never, ever passing up a rootbeer float. Oh yeah, and my favorite food in the world was the hamburger. Worse than Wimpy on Popeye I was

.
My wife never said anything when I shot up to 175 Lbs. on my 5' 2" frame but I could tell that she was worried about me. I was too.
So one day, I finally had had enough and I just made the changes right then and there - no more rootbeer, floats, burgers, and other such nastiness. I switched to drinking nothing but black coffee & water. I still do. I totally cut red meat from my diet and now eat chicken, fish, and fresh fruits & vegetables.
As a special treat, I will eat something sweet on occasion such as ice cream but that is rare enough so as not to affect my overall diet.
So you see, you can do what is necessary to lose weight and become healthier. I also know that there is a tendency to go back to familiar bad habits during times of stress but don't do it - learn to completely control the cravings & urges. You can do this.
Good luck on your journey and please keep us posted here on your progress. BTW, I am also a photographer from way back, and although I don't make my living from it anymore, I still do paid jobs every now & then. My cameras of choice are an Olympus 420 w/50mm 1:1.4 prime lens for quality work and a Canon S3 for everything else.....
- Darrell