I lost 26kgs a few years ago. Put a little bit back on but kept most off. My advice is to find an exercise that you really like because then you can keep it up for a long time and not get really bored. For me it is soccer (first indoor then outdoor) - a team sport - uses lots of calories (around 1000 in a game of outdoor) - requires skill so instead of focusing on how puffed you are you are just focusing on getting the ball - team sport so you know you have to turn up. It may be something different for you. It is very worthwhile spending the time to find out what you is active and you actually enjoy it. Good luck . you can do it.