I understand, and can relate. Experiences make us who we are (or think we are, if the other guy didn't block me yet (oof, shouldn't have said that...)).
Visions come when your spiritual matrix is weakened. That terminology sounds clunky, but its my best stab at it for now. I had something similar after the covid vaccine, which nearly killed me. But, it also made me a Christian... and not a blind one. So I'm thankful, but also never want to go through that again.
If you're going to use substances to induce visions, which I don't think is a good idea, do it with preparation. There are rituals... Idk, never used them, but rituals are very useful. Spend a few years looking inside before trying that. Be able to recognize that parasite you mentioned without aide and figure out how to remove it. Be prepared. Strengthen yourself sufficiently that you're not flirting with death when you try it.