good, bad and ugly!

I am so confused. Good carbs, bad carbs, net carbs.. what does it all mean?!?! What are good carbs and how are they different than bad carbs? I thought that we were not supposed to have carbs at all, but everything has carbs ,even low carb stuff has lots of carbs! My doc said to cut out the carbs, does he mean ALL carbs? Please, help. I've gained back 20 pounds in 6 months, I am desperate to lose it again and apperently carbs are not helping any (also not helping is my lack of energy to exercise.. I can't wake myself up in the morning :(). So please, any help. I need to know this. ALSO.. probiotics.. what's the deal with them? A girl at work lives on that Yakult and I'm confused as to if it's for us and/or what it does. She said they are like digestive enzymes or something, is that something us wls patients should be doing? Good or bad?