Head ache, dizziness may not be due to Gall bladder removal. Very few ppl will have loose motions after surgery for few weeks, otherwise no post surgical issues as such after gall bladder removal. You might be having Gastritis / acidity issues. Consult a Gastroenterologist or surgeon for further management.
Health Tips
Avoid spicy food, deep fries, nonveg, outside food for few weeks.
Drink more water.