The greatest piece of advice I could offer is in suggesting that your destiny largely lies in your own hands, AdrianN. Despite acknowledging that you need to make a start, ultimately, it's your responsibility. Nobody is going lose the weight/increase your fitness for you.
If you don't take those steps, you'll only have yourself to blame for choosing not to take them. However, once that step has been taken, you begin upon the on the road.
Whilst you may consider my remarks to be somewhat harsh, on certain occasions, tough love is needed, allowing you to re-focus upon the task at hand.
Correct me if I’m wrong, but I suspect the main reason behind your procrastination is due to the fact that you may not know exactly where to start. If this is the reason, then I wholly understand.
However, perspective needs to be applied with regard to weight loss/fitness, largely since neither were accumulated or lost overnight. As such, it’s going to take a little time to see gains in both. However, the sooner you make that start, the sooner those gains/losses are going to be achieved.
With regard to diet, as you begin upon your journey, attempt to omit as many energy dense foods (cakes/sweets/pastries) from your diet as possible, since they contain very little nutritional value, whilst increasing your consumption of whole foods. The more wholesome your diet, the less sugar and saturated fat it’s likely to contain.
Granted, portion control and gaining a clearer idea of one’s active BMR (research BMR calculators) also play a part in attaining weight loss, as does ensuring that daily lean protein intake amounts to at least 30% of daily calorie consumption.
As for exercise, in order to improve fitness and the amount of fat/glycogen expended throughout the endeavour (allowing you to change your body shape), consistency is the key. As your fitness increases, the harder and more strenuously you exercise, the greater those physiological and physical gains will be.
However, responsibility ultimately rests upon your shoulders, in ensuring that the chain of events begins, towards improving your current quality of life.