Hey olive, I feel your pain. I went through a very similar situation. My marriage nearly dissolved and my parents left the country. I felt like I was stuck in the middle, crippled by inaction, fearful that any action I took would result in further drama.
Now I’m picking up the pieces and trying to make sense of what and why it happened.
My only advice, make sure that your family and your bf know exactly how this is affecting you and the consequences that will arise from their behaviour.
I failed to do that properly.
And don’t accept ultimatums, unless you truly think one party is definitely trying to harm your well being/marriage/family.