I've been through hypoatrenemia and it was honestly just painful and incredibly confusing. I wasn't trying to kill myself, I was trying to stay cool in a warehouse. I don't think I could've actually made myself drink enough to die if I was trying, because my stomach only holds so much water, and I was getting so out of it that I almost couldn't go home. My boss was talking to me and I didn't hear a word she said to me. I couldn't work, hear, or see outside of what was right in front of me. Plus drinking that much water fast is really hard.
TLDR, I don't suggest it. you'll feel shitty, probably puke up some of the water, and be so goddamn disoriented and confused that you may not even be able to get down enough water.