If you want to reach and maintain normal weight permanently, you have to improve your eating habits permanently. Your mistake is to concentrate excessively on reaching a certain weight. Try instead to concentrate on creating new habits for the rest of your life.
If you find it difficult to change all your habits do it one step at a time and you will gradually find the new food natural and good. Use this new diet when you lose weight and just go on with the same diet when you have reached your goal.
You write about your longing for sandwiches and cakes. Try wholemeal rye bread with ham or turkey and a lot of vegetables at your sandwich, and a couple of wafers with sliced banana between them as a replacement for cakes.
Avoid sugar and fat and base your meals on salads, vegetables, potatoes, roots, berries, fruit, porridge, fish, lean meat, low fat milk products and small amounts of olive oil.