Welcome Peter
I'm sorry to hear that the results of your exam were not good
The silver lining, though, is that moments like that are some of the biggest motivators to make healthy decisions about your life!! You Can Do It!!!!!
There are several sections on this forum, so definitely take a few minutes (or hours lol) and read some of the posts
There are so many different types of eating plans (calorie counting, weight watchers, low-carb, etc) to choose from, and it can be overwhelming. My recommendation would be to find a diet that works well with your lifestyle...if you change it too drastically, it can cause binging/rebelling, and that leads to yo-yo dieting.
Good luck with your weight loss journey!!! ^_^