It is certainly not easy, no.
I was very lucky in that my wife also did the diet with me, so that was really, really helpful.
But I did not stick religiously to the shakes, I did occasionally have a salad or some nuts or an apple, etc.
Bear in mind that the shakes and soups diet is basically based on the Newcastle diet, which I think (not 100%) was three soups and shakes plus some veg or a salad every day, so was perhaps a bit more flexible than any diet you may be on if they are asking you to only have x4 a day and nothing else?
I also found that drinking lots of water helps, as that fills you up, plus I have had kidney stones in the past, so I tend to drink lots anyway!
Also maybe look at the times you are eating the shakes, try to either space them out more evenly over your waking day, or alternatively have two at once early on, then two again later on.
You just have to find what works for you really.
As long as the cals / carbs going in are less than those that you need, then the weight should come off, and thats what its all about really.
It helped me to think about the bigger picture and the potential benefits, eg: weight loss, less stress on my organs and joints, possible remission from diabetes, lower risk of other health issues, better mobility, etc, etc.
Those all outweighed the short term and temporary issues and hunger associated with the pathway diet.
Stick with it, stay positive, it does get easier (or it did for me).
You can do this, you really can.... 😎