Amatryptaline works for some,not all

I tried it for pains in my arms and may have been ok for my IBS too,but I got drousy,light headed,palpitations but when I started feeling morbid, i stopped them because as an anti depressant I should not have felt the opposite way - but other people I know say they take them at night for a good sleep,but when my mind gets active at night and with wild dreams and hallucinations,made me feel exxhausted the following day....so good for some...but not for me.....