One of those things are immediately solvable. Your can't sit in solitary and get upset that you get little real life interaction. Either own it and be happy or change to make yourself happy. It's not possible to live a perfectly ethical life and be happy.
yeah, i did with my last partner too but i wouldn't exactly recommend it as the first option considering how unsafe it was & some of the experiences my friends have had up there
oh yeah, i've heard of a lot toxic behaviour coming from discord but it truly depends on the circles you run in. for the record i had made a brief attempt at dating while on reddit (i know) and that was pretty disastrous.
Meet people in online social places. I met my wife in school but I also have a great friend who I flirt with, my wife knows, who I met playing an MMO. We do want to meet up but she lives half the country away and she's still in college. Just fine a community you like and eventually you'll open up to someone.
I meet friends on discord and occasionally in nsfw sites. My life sucks though, don't ruin your life this way, just meet introverts at the library or something.