Open Question: Are the 4 650 mg Tylenol caplets I take a day safe?

I have been taking two Tylenol tablets for the past few years … This is a daily 650 mg tablets, 2 times per day. I think this is to alleviate neck and back pain in my neck, because of arthritis and back. At first, doctors prescribed drugs (do not remember what) .. but the follow-up blood tests show that this is my liver adversely affected. Then he suggested that I switch to Tylenol. I Tylenol arthritis pain. I think it helped with a lot of discomfort, (I am a medical plan to tell me before the 'acute cartilage deterioration in my spine and neck'). It ruined my liver?