I am suposed to start my pureed diet next week, and I am afraid I wont be able to eat. As of now the protein shakes and crystal light and an occasional sugar free pudding is the only thing Im  able to put down. Im scared I wont be able to eat anymore.

It's really personal preference.  I prefer unsweetened almond milk.  

First off, start tracking every single thing you put into your mouth with something like my fitness pal.  From there, work on getting back to your basics.  Here are mine, yours might be a little different.  

1. Prioritize protein and water
2. Deprioritize carbs, especially the refined and processed ones
3. Make the most of healthy fats
4. Eat three meals a day with no snacks
5. Avoid liquid calories (breakfast protein shake is the exception)
6. Weigh portions, log everything consumed
7. Eat mindfully and with no distractions aside from real live people
8. Move as much as possible
9. Weigh myself daily
10. Be kind to myself

I drank protein shakes pre-op, and I drink them post-op too.  I like my morning breakfast shake.  Just be sure to read the ingredients - it should be whey protein isolate and the carbs should be in the less than 5 range.  

I think you should change your diet plan, and find one that is easier for you and more convenient for your life style. there are other weight loss program that may or may not work for you, try more eating green, for your busy day try to have drinks that would help you loos weight and keeps you energize at the same time. I been to a lot of weight loss program somehow i get frustrated, i change my diet plan instead and do all green and raw. even trying out green tea and also not all tea work for me except this Starter matcha that i tried and some banana and oats for breakfast and no dinner anything green at lunch. 

Image Source: Starter Matcha