How can I help my family become more accepting?

So for the past few years there’s been a little trouble in my family. My cousin, born female, came out as...well a lot of things. The first time they (I’ll use their preferred pronouns) came out they said they were a lesbian. My family accepted them even though they are really conservative so it was great.

Next time they came out they said they were bisexual. My older family members were confused and said some phobic things but they apologized and it was great again.

The third time they came out as pansexual and agender. Of course my family was very confused and kinda just went “okay then...”

Now this fourth and last time they came out as gender fluid and said they only will date men. And this is when my family just went off. They were angry that they have changed their pronouns 3 times so far (first she, then he, now they/them) and changed their name (Salem and Mitchell) and this causes my cousin to have a complete panic attack.

Is there anyway I can help my family become more accepting? And is this normal? I’ve tried to talking to them but they just say they don’t feel right with their identity. Any advice please!