Your story sounds a lot like mine. I didn't get to 270, but I was getting around 230 before I decided to change things. Fortunately, I didn't have a job at that point, so I got to shed about 1/3 of that weight in ~6 months by doing lots of walking, hiking, and improving my macros (i.e. cutting out sugar and high carbs). Today I'm at 150.
In my opinion, it really doesn't help to tell people what kind of exercise they should be doing. Just sweat. Do whatever it is that you can do consistently. No matter what, you are almost certainly burning more calories than you did sitting around. Combine that with better macronutrients, and you'll almost certainly lose weight.
Once you get slimmer, this can get more difficult because people with more body weight have a greater basal metabolic rate. What I do now when I need to shed some weight (sometimes I get up to 160) is do those things you did before but also eat less. I calculate my BMR, divide it by half, and only eat that many calories. This is a short term strategy, not a long term one.
People argue endlessly about which exercise is "best" but the fact is that the difference between forms of exercise is a rounding error compared to the difference between ANY exercise and being completely sedentary. The most important thing is just to find something that you personally enjoy and don't get inured doing. The constraint for the vast majority of people is just motivation.
In my opinion, it really doesn't help to tell people what kind of exercise they should be doing. Just sweat. Do whatever it is that you can do consistently. No matter what, you are almost certainly burning more calories than you did sitting around. Combine that with better macronutrients, and you'll almost certainly lose weight.
Once you get slimmer, this can get more difficult because people with more body weight have a greater basal metabolic rate. What I do now when I need to shed some weight (sometimes I get up to 160) is do those things you did before but also eat less. I calculate my BMR, divide it by half, and only eat that many calories. This is a short term strategy, not a long term one.