Same story here! In September I had a horrible panic attack/literal hallucinations from an edible and spent like 8 hours with intense suicidal thoughts. Since then, a lot has happened—a lot of existential questioning, depersonalization, derealization, panic attacks, etc. However, I certainly feel a lot better now. I definitely think you'll feel better too.

If I were you, I'd avoid drug use, though. That includes psychoactives like weed, psychadelics, dissociatives, etc. They will not reverse what has happened. You know it yourself: You can't make something unhappen. You've had certain realizations and this cannot be undone. Instead you have to come to terms with the nature of these realizations and your reality. Once you've acclimated to this, it gets a lot easier (for me at least). To do this, I'd absolutely see a therapist/counselor. Talking about my feelings with a good therapist has been very helpful and sort of clears my head. If you can't, family and friends are also possible. Now when I depersonalize, I don't panic as much. I also am slowly stopping all my existential ruminating.

Please PM me if you want to talk about it more. It will get better.