Hi,sorry you're feeling in a bad way,try and appreciate how much you've lost so far-its a great achievement!
I used to be on slim and save,and the losses are great,but it can be a difficult diet to stick to-being in the right headspace is essential,I lost my first stone on slim and save and have now moved to cal counting.
Usual loss in 4 weeks is about a stone,it really is one of the fastest diets if you can do it,and alot of the meal replacement products do taste good as they go.
Good luck with what you decide .