As someone who has recently lived a similar situation with a IRL friend, let me tell you some advice. You can try talk to your friend, and you tell him/her why you think they should seek help. If he/she doesn't want to see it and keeps doing all those abusive stuff to you... well, then you can be at peace knowing you tried to help, but then it's time to leave.

That's exactly what I did, and when he didn't respond I left that abusive relationship, and my now ex-friend kept displaying hate and resentment to everyone around him, until he lost pretty much everything (family, friends and now job). I don't have any regrets though. My emotional health is quite valuable to be with someone that abusive.

Some people just don't want to be helped. (Boy, did I learned that the hard way)