i graduated med school in 1993. i was so spent that i took a year off before tackling residency. i'm well aware of the toll that 4 years of medical school takes on young minds.
my first advice is to know (and write down) why you're putting yourself through this ordeal. no one else knows why you're doing this. all of your professors, colleagues, and patients will assume that you've made a firm commitment. so whenever you're beaten down and waiver in that commitment you'll need something (or someone) to refer back to and remind you of your reasons.
it might be because of a previous medical experience. or a family member in the medical field who encouraged you. or it could be that you want to return to your community to offer your skills. or it could be the intellectual challenge. or maybe it's something more shallow like money or prestige.
secondly, find a group of friends. making it through medical school is exceedingly difficult when done alone. it's near impossible to stay on top of every subject and every medical condition. but a study group helps to bridge that gap. and it's also less lonely that way.
third, know when to focus. i loved to exercise and play sports. really, really helped with the stress. maybe you highly value time with your family, spouse, or children. maybe you cooking, or reading, or some other hobby. but remember that there will be crunch times, like right before an exam, when you must put those activities on hold.
fourth, i'll throw this out there but it might not be what you want to hear. you should have a fall back plan in case you don't make it. many don't. maybe you get EMT training. or phlebotomy training. or a pharmacy degree. or a physical therapy degree. or a nursing degree. etc, etc.