Was quite terrible to read, but here's some advice.
Change your IGN and Discord tag if there's an overobsessed wacko doing that kind of stuff.
The worst they can do is use their words. As long as they don't have your IP, you are okay. If somehow they even manage to grab an IP, anything done to it (doxxing, DDoSing, etc.) is a federal offense and can be reported to the proper authorities (atleast in the US, not sure what country you're in, but most places have laws against this stuff)
I've been doxxed before, and best advice I got is nothing bad can happen as long as it doesn't turn physical, as in having packages mailed and such, or having unwelcomed "visitors" show up.
Once again, sorry to hear about that. That crap can be scary. If it ever happens again, block them and /ignore them, reporting them was the best call in that situation.