Hi Jan,
The first thing is to pat yourself on the back for realising that there's something you want to sort (your weight) and you've already started looking into how to fix it (slimming world and this forum).
The best thing is just to forget your past and accept where you are now, and get the determination and motivation you need to start losing that weight and eating healthily.
Have you done slimming world before? Even if you have, I'd recommend going to classes as it's a great help, loads of information and definitely a good way to lose weight. This forum is fab for info and ideas too.