I skipped the 4th of July last year to study for the MCAT. It wasn't worth it, and this is your permission to take the day off
Last summer I stayed home on the 4th to study while everyone I knew was out. I want to say it was some disciplined hero move, but I barely retained anything that day. If you stay home to work, all you're really going to be thinking about is what you're missing.
So for anyone who needs to hear it: take tomorrow off. The MCAT matters, it may be one of the most important tests of your life, but one day is not what decides it.
The guilt runs both ways. Grind all day half focused and you retain almost nothing. Take the day off and spiral about it at 10pm and you never actually rested either.
The middle ground: wake up early, knock out some Anki cards or a light review block, then close the laptop and go to the pool party or whatever. Be all the way there. Your mental health is part of your prep, not a break from it.
If you don't know how to fit rest days into your schedule without panicking, drop your test date and your resources and I'll help you map it out. Learning to schedule rest was the hardest part of my prep.