Don't give up entirely on the shakes, soups, etc. I have found that some things I didn't like the first couple of weeks, I now like or at least find acceptable. For example, I really didn't like the tomato soup, but now it's one of my favourites. Also, because the products provide all your nutrition, perhaps it might help to think of them as medecine that you just have to get down to get better (aka lose weight).
Hang in there and good luck with the tetras. If you get the bars, just be aware that they are more caloric (shakes/soups/porridge are approx 150c; bars are approx 220c), higher in carbs and you will need to drink more water to digest them.
Good luck!