I have been there and tried a lot of different exercise and diet types. I was doing 1-1.5 hrs at the gym 4 - 5 days a week, and it was high intensity work outs. On the off days I would still be doing a lot of walking and incidental exercise - minimum of 10,000 steps. According to websites I thought I needed to do that much to lose weight.
Then a lady from my gym who was a nutritionist put me on an eating plan and also gave me some exercise tips. I went from eating low carb and exercising 4 - 5 days a week, not losing any weight, to working out for 20 mins 3 days a week and being able to eat more of what I wanted. In 3 months I lost 10 kgs and have now kept it off for another 4 months.
The key is challenging your body and not letting it get used to the exercise you're doing. You need to do interval and change up your heart rate throughout the 20 mins to keep your body guessing. This not only burns calories during your workout, but fastens your metabolism for 24-48 hrs after your workout which is overall more beneficial.
I'm happy to share experiences with anyone looking to lose weight and not getting results *edited to remove spam*