I currently live with my grandmother and dad after escaping my abusive mother, I try to set boundaries but I get laughed at...

My grandmother just came out her pants down and showed me her underwear, I told her to leave because I don't want to see her ass.

She left angry because I refused to laugh at the fact that her underwear looked like a thong. I tried talking to my dad but he laughed because it was funny I broke down and cried saying is not funny i have boundaries.

Last night I was touching myself when my dad just barges through the door... After i told him i was having alone time and to not disturb me.

My mother never cared about my boundaries but i least i could close the door and be alone. How do I fix this, I feel so small and helpless