Help...I am worried
I suggest you talk with your MD and get labs drawn. This can either be your surgeon or your primary care Doc. You may be low in your electrolytes, protein, anemic, etc. Are you getting at least 60 gm of protein in a day? 64 oz of water? What prescriptions are you on? Do you take any BP meds, they may need to be adjusted.
Get a physical and your labs done, then you and your Doc can be in a better position to judge what you need, be it change in meds, B12, or whatever.
Good luck!
Sarah