Close friend of mine has been overdosing on tylenol pm for 2 years help please?

I have known something was up with my friend for a while but finally got her to talk to me. Now I'm not really sure what to do. Her husband approached me with his concerns for her safety and when I talked to her she told me she has been gradually taking more and more tylenol pm to help her sleep through the past couple years. She is now up to 20 plus pills a night and vomits almost nightly because of it, but then takes more to 'help her sleep'. Her pulse rate is through the roof all the time. Her husband has said that about an hour after she takes it she gets very irritable and snippy. Her vision blurs and she takes forever to fall asleep now even with it. Apparently this has been going on for a couple of years and is getting gradually worse. I don't know how to help her at all, I've never even heard of anything like this. Has any one been through this or can give me some advice on how to get her some help? I got her off of it for a week in favor of melatonin but she said it didn't work on her and that she was having really painful muscle spasms. Please anyone help if you can. I appreciate any answer. Thanks so much. Oh also what damage has she likely done? Maybe if I can give her a definitive answer on that it will get through to her.