I'm going to echo what oyster said. Diet is, indeed, the most important when it comes to weight loss. Calorie restriction is the key here. You can eat all the 'healthy' food you like, but if you consume more calories than you use, you will gain weight. The best way that I have found for restricting calories is to track all food intake. There are plenty of apps out there that can help you do this. Loseit is great. It's what I use. MyFitnessPal is also quite popular. It isn't nearly as good since Under Armour bought it, in my opinion, but YMMV. This, of course, is not to say that exercise isn't important. I would argue that it's necessary to efficient weight loss; however, you can't outrun a bad diet. I would suggest getting on some sort of weight training regimen in order to maintain muscle mass. Starting strength or stronglifts 5x5 are both good options. Keep up the cardio too. Alternatively:
I totally second tracking what you eat in some app that has a large database of food to pick from. Myfitnesspal I can account for. I personally used the IIFYM method ("If It Fits Your Macro's") to get weight under control. The idea is that you define a weight loss goal, e.g. half a pound per week, and it will calculate an upper bound for the amount of calories, fats, sugars and carbs (the macros) you can eat every day. You can eat whatever you like as long as you don't go over those boundaries too much. Myfitnesspal also allows you to input exercises, which raises the amount of calories you can eat in a day. Basically, it's a bit of work to fill in what you're eating every day, but it is extremely valuable information to change your diet because you can just see that eating PB ruined your fat macro. See it as a scientific food experiment, N = 1. There are so many foods that seem healthy but once you log them it becomes obvious that it's what's keeping you above your desired weight. Cut or limit all foods that are high in certain macro values and down the scale will go.
Cheese was the thing killing me. I'd make a chicken wrap with cheese and spinach, and half the calories were the slice of cheese. Crazy. I've been using MyFitnessPal for about a month. I don't love it, but it integrates with my Garmin fitness watch. For me, to feel sane, it isn't a travesty to deliberately cheat, i.e. knowingly go over my calorie limit occasionally. For me personally, it is terrible to lie to myself about how terrible some food is or how much I ate. The more honest one is with themselves and their calorie tracking, the better. (Though I'm on vacation right now and my log is a mess these last few days. There's no cell service, making it a bit more difficult.) MFP tells me my limit is about 2000 calories/day. Some days this seems hard. I find it's easier for me to burn 200 calories exercising and eat 2200 calories than to do nothing and eat 2000. But again one needs to be honest about the exercise. I've heard it said "it's hard to outrun a donut."
I've been using MFP for about four years now, and LoseIt for about 18 months prior to that. It gives me 1800 calories. Or, about 400 more than my 3-year old is supposed to get. Then it says I burned 1100 calories shredding brush. Whatevs, MFP.
I entered 10 hours of hiking into MFP. It told me over 5000 calories burned. It was a long day, and I'm sure I used a lot of energy, but that's ridiculous. I'm not sure I'd believe anything over 2000. The food calories seem to work well for me, though, and exercise in smaller amounts seems reasonable. I don't think exercise calories scale correctly.