What Are The Side Effects Of Implanon Birth Control?

I've had the Implanon implant for around 8 months. I went to the doctor after 6 months and explained that I was having some mental side effects such as mood swings, anxiety and loss of libido. Her response was to put me on a 10mg/day dose of amitriptyline. I only took this drug for a week before calling her to discuss what terrible added side effects I was getting. I've had bad reactions to Citalapram and other contraceptive drugs before (various pills and the depo injection) my question is should I ever have decided to have this implant and was the Dr heavy handed in prescribing the amitripyline?