Nortriptlyn

Please can anyone help me! I started nortriptlyn 2 weeks ago to help with nerve pain and since I started it I've been feeling very very depressed! At least I think it's the tablets has anyone else ever suffered with these tablets. They were to replace pregabalin which didn't work. But I feel the worst I've ever felt with severe depression and can't do anything, please can anyone advice me I don't know what to do!