Anxiety and panic attacks with epidural

I have suffered from anxiety, depression, and panic attacks for years. I am taking clonazapam 1mg, 3xday, and Seroquel 400mg 1 at bedtime. I am probably going to have a total hysterectomy very soon. My biggest concern is what kind of anethesia to use. I am 51 yrs. old, average weight,good blood pressure (on the low side) but heavy smoker (2 pks. day) I am afraid of gen. anethesia due to the heavy smoking, but also scared of epidural, as if im in a semi awake state during surgery, i may start to have a panic attack, which would include difficuly breathing!...So what should i choose??...My OBGYN knows i am a heavy smoker, so has sugested the epidural..I am really scared..Anyone else in the same situation?..Or have any adivce would be great!! thansk so much!