Hi and welcome Lindsey. I must admit I know nothing about Slimm, but if it is a meal replacement programme it is likely to be similar to SlimFast.
Is it the one you make up with water rather than milk? If so, it might be a VLCD rather than meal replacement - SF allows you a total of around 1360 calories a day.... 2 x 230 shakes or bars + 3 x 100 cal snacks and a 600 cal meal.
Anyway - come along in - if the principles are the same there will be tips and hints that might help you along on your weight loss journey.
Good luck!