How do you mentally prepare for Easter family gathering ?

Hey there, my family has a gathering this weekend and I have to go. I'm happy to see my grand parents and the country side in general, but I don't know how to handle the whole sharing of the room with cousins and siblings. They think since I'm young (I'm 20) I should have the biological clock of a party animal. But I go to bed at midnight max because otherwise I'm a worse mess than ever if you know what I mean.

I also can't focus on why stuff during family gatherings. Like, I always try to just go in my room and do my things but I can't. I just can't focus on anything there, because the sadness overcomes me.

I really wish some of you could give me advice please. <3

Edit : I take all kinds of advice !!!! even the unhinged ones