You must be close to the 50 hours for the Amitriptyline to have worn off.
Amitriptyline is in a group of drugs called tricyclic antidepressants. Amitriptyline was released for sale by the FDA on 3/2/1984
Effexor belongs to the group of meds known as SSRI/SSNIs. Effexor was released for sale by the FDA in 1993.
Please follow your physician's orders and stay on the Effexor.
If you continue to have problems, I would contact your physician for further instructions.
Remember as you read through your posts from members, we are not profesionals and broad comments re meds need to be taken with a grain of salt.