Epidural lower back spine injection recovery time/and side effects

HELP PLEASE! I got an epidural spine injection and my lower back L4 and L5. At night time I get cold arms and thighs with cold chills and slight body aches. It’s been a week so far with these symptoms, it’s weird I don’t get them during the day just at night. I get dry mouth all day too, how long would these symptoms last I read it supposed to be two days and other places 2 to 3 weeks, can’t get a straight answer. My legs feel slightly weak and slight discomfort, but at night time I feel really sick for about 5 mins and sometimes sick all night. Hot flashes too, any idea if this is a serious concern or just side effects that will go away ?