About 6 To 7 Weeks Ago I Took The Plan

About 6 to 7 weeks ago I took the plan b pill. Right now I am having a lot of trouble just coping in general. I am very depressed, I feel like crying pretty much all the time. I am also not eating hardly at all which is causing me to drop weight and am having a lot of "death thoughts". I felt this same way after stopping the birth control pill that I was on for 5 years to have my now 17 month old son. Is this a hormonal imbalance like I believe and how long can it last?