Loyal Defender

I'm feeling really stressed out. My parents wanted to go to Route 66 in New Mexico, since it's the last chance for a family trip before my stepdad has to leave for nine months. I declined, offering a week's worth of schoolwork to do while they were gone, but they began pressuring me, saying it's 'an experience' and 'I'd really regret missing out', and using the last chance excuse on me, and even wound up AGREEING when I said I felt bad, and they were like, 'If I were you, I'd go, so you SHOULD feel bad for declining'. I honestly got back from Utah twelve days ago, and already they want me to go on another trip. 
They're telling me 12 hours out of my day is nothing when I've spent 60 with them during our trip to Utah.

I feel terrible for not wanting to go on a last-chance trip, but I just don't want to go. I'm not wanting to stay home JUST to play video games either (although admittedly that's part of my plan). The real reason is because I just want to relax instead of going on another big trip right after we got back from one.