Hi sam,
Sorry to hear that you are poorly.
My hubby was prescribed Amytriptyline (not for depression - but to help relieve constant headaches). Initially, the dose was increased gradually, to check the mgs suitable. When he came off of them, again this had to be done gradually.
If your GP recommends that you stop the dosage, they will put you on a reducing regime, because stopping too quickly can be detrimental to you. My hubby was on 40mg and reduced by 10mg for 3 days, until down to 10mg before stopping altogether.
Take the advise of the other posters and see your doctor.
take care
n00dles