I haven't used Discord in a while, but it became so that now I have to use it for communication with certain people getting support for some services that I use. What I'm doing currently is:
using a separate randomised e-mail address only for the Discord account
using a randomly generated username
no profile picture
tweaking the settings as best I can for privacy
Other than these points, I'm also being wary of talking about anything personal on Discord. Would you add anything so I can be even safer when using Discord?
Note that any text send to discord currently stays there forever. I don't know when, but you can bet your ass they will be investigated for a violation of the GDPR, which hopefully stops that for good.