I'm sorry, I went through something similar.

I can speak about drugs. I would say weed is an option to survive, I wouldn't say it's a bad one nor a good one. It brings negative and positive effects. It's easy to live for the high and become addicted in my experience. High cbd marijuana is pretty good and with a low thc content, it can be even better imo.

Mdma is worth a try. I wouldn't go for ayahuasca or other psychedelics (lsd, shrooms, DMT,...). I strongly believe they can help but it can quickly become overwhelming if you are a little reckless with the dosage or just not ready. While a bad trip can be beneficial, I wouldn't play with my precarious sanity again. It's playing with fire if you are suicidal and prone to flashbacks. Flashbacking for what seems like eternity can really fuck with your mind. If you do try, don't do it alone, experienced trip sitter and not some shaman in the amazon jungle. Anti-psychotics can stop a trip but it's not the safest way to end it.

Meditation, exercise, therapy are all valid options but you need time to heal. Maybe reach out to your brother ? Or at least to someone ? You don't have to go through this all alone, it's already isolating in itself... Have you read the books in the sidebar ? (Pete Walker is great)