how to cope with breakup..

he sent me this, this morning. The night before we had a huge fight and he told me to never come over again. So I didn't come over last night and he asked why and I said cause you told me not to. So he calls me negative and that hes been waiting for me, etc. I don't want to be with a person who thinks of me this way. I have an amazing personality and everything he said is not true. I have been with this guy since Nov, 2014. He recently got into a fight with his family. So he thinks the only way to get back at them is to buy heroine and OD. He already had a benzo problem, now he's doing this. Would it be the right thing to do, to tell his mom? He always accused me of running and telling on him when I am mad. But I am not mad, I just dont want him to do this to himself. That drug is highly addictive and he could kill himself since he's never used it and doesnt know what hes doing.. I dont know what to do.