That's a tough situation.
My parents have cancelled 2 holidays because of my hospitaliations. Both were international holidays. First one when it was my first admission and first attempt when I was 15, I was glad they cancelled it because I was so distresed at the time. The 2nd time was last year (I was 18) and they had arranged to go to England (im in aussie land so it was a expensive holiday) for a couple months, I felt so bad that I had messed up another holiday which they had wanted to go on for years. But I needed their support at the time and am grateful that I didn't have to actually ask if they could stay. They did go away for maybe 5 days interatate late last year when I was admitted cause they knew I would be safe if I was hospitalized ( I wasn't hospitalized just so they could go away, they booked it after). They did need a break

But I don't know your specific circumstances but I think they would rather you alive then go on a holiday. Let them know were you are at and see what the options are