Is gallbladder surgery dangerous?

please help me to better understand gallbladder surgery,i'm having surgery in a week &i am extremly nervous i have high blood pressure that is sometime not controlled,i also have hyetial hernia but my dr. says i've got to get this gallbladder out i hurt so badly sometimes i needed up in e.r, last week in severe pain..but i'm nervous about surgerybut mostly about the anithesia(i had surgery years ago & was very hard to wake up..&was chattering when i finally woke up(as if in cold)i also have av nodal reenetrant svt heart.what if i have an episode of svt or by blood pressure shoots up?please tell me what you think...