Exercise indeed is very important, but the most important part is to count the calories you take in so you could know how many calories you should lose. That is the perfect way and it is also known as calorie deficit. Maybe you’ve heard of it. Anyway, if this doesn’t suit you you should try a keto diet that could be right for you. When I decided I needed to lose weight I used this https://kitodiet.me/ to help me. Obviously I did a lot of sport too… what is a diet without exercise? 
All in all you can do it if you believe in yourself!
