Would 900mg of Diphenhydramine do it?

I attempted once with 1,250mg of diphenhydramine before but still survived. It did feel pretty horrible, and the hallucinations were insanely real. I recently had a lower lobe resection and also removed a part of my middle lobe because of an AVM at the very end of October this year. I really don't have enough money to get more, and maybe I'm just delusional to think that I will magically die from such a small amount, but please give me more information on this! For context I am 16, 155cm, and 45kg (sometimes 46kg).