Feeling So Weak in POST-Operation Weight Loss Surgery Q&A Posted September 5, 2012 I was really afraid of this too and felt the exact same thing you're describing. I focused primarily on continuing to stay hydrated that first week to allow any swelling to diminish until my second week when I could drink normally. Then, when you are able to add in Protein - I love Shakeology - it made me feel like a new person again. Just give it time, and dont' worry too much. Once you get in more nutrients and after your stomach isn't as swelled, you will feel much better. I was so worried I'd be SO light headed and tired like I felt the first week, but now I'm only 16 days post op and feel almost normal again!