Yes, it might be good for you to get some distance from your mother and sister right now. If you find that it doesn't help, you can always reconnect with either one of them later. (That's what I eventually did after distancing myself from my family for a few years.)

I hope mental health services can help you. If they have support groups there I recommend that as you will find more empathy talking to people who have had similar experiences.

--Ceara1010