Narcissistic partner... Help.

How do I end things completely with a narcissistic partner that says he will kill himself if I won't be with him? He lives with me and has nowhere to go right away... He is always throwing pitty parties for himself over me wanting out of the relationship and he feeds me lies over and over telling me that he will change this time, even though he has already had numerous chances and just broken me... He won't leave me alone. We have two kids together and I don't know how to deal with this. 😭😭😭 I need help!