Desperately want to book my flight - but it’s 15 hours. Any advice on feeling stuck

I’m not worried about a crash as much as having to be in that tube for FIFTEEN hours. It seems insane to me. It’s actually 15 hours from Toronto to HK and then another flight for 5 hours to my destination.

I’ve done Toronto to India and it was two 8/9 hour flights and it was ok. It’s been a while since I’ve gone though so I have no frame of reference for this my flights recently have only been 5 hours.

I want to go but my anxiety at being stuck and trapped is increasing, I actually didn’t go on a scheduled trip once.

My worry is going insane and being taped to my chair or recorded or just screaming for hours like a lunatic since 15 hours is v long

Any advice, has anyone managed this specific fear? I don’t want to book and lose the money and I’m hesitating to book but I want to go on a trip so badly