I'm sorry to hear this, OP. A few thoughts of mine in no particular order:
-Med school can be like drinking from a fire hose as some have said. It's hard to figure out how best to study at the beginning, how best to drink from this fire hose.
-Also the culture of medicine can be full of pressures and very unforgiving.
-I know this is just the start for you, and it seems like a huge deal to you, but it's not as bad as you may think to fail in MS1 or take a LOA. Or at least if you're going to fail or take a LOA, it's better to do it in MS1 than later. Just trying to offer some perspective.
-Again it might not be a bad idea to take a LOA, especially in MS1, where at least from my perspective it won't look so bad and have the least impact on your future career. Just make sure to talk to people who know you in person (e.g., school counselors) and can offer you some guidance as to whether a LOA is really what you need or not.
-If you do take a LOA, just make sure you also take the time to see a counselor (nothing wrong with that) and any others you think can help you get back on your feet (friends, family).
-Also if you do take a LOA, just make sure, after you've hopefully healed, try to figure out how to study, what works best for you. Talk to classmates or others who can help you. Everyone is different in how they learn the material, but you'll eventually have to learn it.
-Hopefully others with more experience and a better perspective like SDN Advisors can reply.
Good luck, OP.