Hi Fresia; I don't fly well (motion sickness), so I take 2 gravol before I fly.
I would have a hard time in that situation as well and when I have gone away to stay with a boyfriend's family I always regret not getting a hotel room. If you can afford the extra cost my suggestion is getting a hotel room. I travel for work and have no problem sleeping in a hotel, but somehow sleeping in someone's house disrupts my sleep, causes anxiety etc. Since your family knows about the BP you can just explain that you need your sleep etc. If that's not an option racee's suggestions are excellent. Have a safe trip.