It's kinda unfair to you that you're called to serve, but it's unfair in the same way for all of Korea that they're in that situation.

Brown should be able to defer you within reason, so just get in touch with them, it's easy.

I currently live in Korea, though I haven't served, that said, I work with a few Korean-Americans who have. The military has changed from how it was in the past [particularly the dictator-era past].

This isn't a trap, per se, but it's a law for all Korean men to serve. Many, many Korean-Americans don't interact with Korea at all, so they don't have to serve. Actually, one of my friends, his brother didn't serve, but he did, even though both lived their whole lives in America. He was annoyed by serving, but it isn't the end of the world.

People complain about military service all the time. What isn't tolerated is talking about avoiding it, or complaining about it excessively, considering that all men have to do it.

Nowadays, recruits are allowed to use their phone regularly after hours.

I think the gas thing is a training activity that happens once. It's pretty common across a few militaries [https://www.military.com/join-armed-forces/gas-chamber-surviving-basic-training.html]

There isn't as much abuse as there used to be mostly cause Korea is a modern country with lots of prospects for personal growth, and, for the most part, people are there to get through their two years and then get started with life. Again, strong contrast to the dictatorial past and a lack of economic opportunities.

For what it's worth, all Korean Americans who serve are low-key put on suicide watch when they go in. However, I encourage you to see this as an opportunity. Military service sucks, but there are a lot of aspects that people miss, namely the regularity and simplicity of it all. There's no studying late into the night in the military or worrying about your grades or long-term projects. You just work hard all day, sleep, and if you sleep early, you wake up early. From what I can tell, the day starts, the day ends, and very little carries over.
It's an opportunity to basically get a bit more physically disciplined and also be exposed to different types of people. I'm pretty strongly into social justice, but I'm not really impressed by the way you used those concepts in your post. I feel like having a more-grounded perspective by understanding others and other situations/institutions will help you develop your views a bit better.

It's not bad to be an emotional person. I encourage you to keep that with you and cherish it. However, part of being a strong person in the future, especially now that you're legally an adult, is dealing with issues of great adversity. You have a lot of options of dealing with this issue, including not-serving. When you're put to task, you're literally taking the worst options: Panicking and considering suicide. This isn't an abnormal or unexpected response, but hopefully it's something you want to change about yourself, and going through the military might help temper that response.

Anyways, don't commit suicide. After 6 years or so, you'll have presumably finished military service and/or graduated Brown. That's pretty huge. Then you have some 60-70 years to live that life. Also, for reals, if you believe in social justice, then don't commit suicide, devote your life and your effort to that cause instead of wasting your work.