A big part of a lot of people's problems is that they feel sorry for themselves. Oh, I'm fat. Oh, I'm out of shape. What am I going to do? Woe is woe is me.
Put the fork down and get off your ass. You didn't get into this situation overnight and you're not gonna get out of it overnight. Start monitoring your diet. Don't get caught up in one diet or the other. If you refuse to change how you eat then just go with pure calories in and calories out. No, that's not the most efficient method but you can still eat your shit if you just have to have it. Log your exercise and calories burned. Once you understand how hard it is to burn calories is that small slice of cake still worth it? You willing to put in 20-30 hard minutes for that cake? Celebrate the wins. You can only walk one lap around the block and you're spent? Well, that sucks but you made it one lap around the block! Keep doing that. Very soon you're gonna be able to do two. Then three. Then four, five, now you can jog around the block once. You just improved 400, 500% in short order and celebrate that for what it is - massive improvement! Improvements by magnitudes. Keep it up! As you dial in your diet more and more you'll find out that you don't actually NEED to eat that shit.