The answer is pills, including benzos like valium, are notoriously garbage as a CTB method, even in high quantities.
Diazepam has a very wide therapeutic index, which means it takes a lot to kill you outright. It's long acting, yes, and it can depress the central nervous system heavily, but on its own and even in large doses it usually results in heavy sedation, confusion, and prolonged unconsciousness rather than death. Especially if you're otherwise healthy and alone, it's far more likely to lead to a coma that lasts hours or even a day or two or gross things like vomiting while unconscious, which poses choking risks. Sometimes, awakening later with grogginess, memory loss, or serious organ damage if mixed with other substances or delayed discovery is on the cards. If someone finds you, intervention with flumazenil or intubation will happen.
To actually die from benzos alone, the dose has to be
absurdly high, or mixed with respiratory depressants like alcohol, opioids, or barbiturates.
100 to 200 tablets of 2mg diazepam
sounds like a lot, but that's only 200mg to 400mg total. That's far below what's considered lethal in most documented cases. There are people on prescribed regimens that take 60–80mg per day and taper off slowly. Tolerance plays a role too like if your body's used to CNS depressants, you'll metabolise even more of it.
I don't say that to be dramatic. I say it because people have
tried, and they've come back with horror stories, liver damage and/or months of recovery.
Read this post about non-methods! It's super helpful.
Be careful. Please choose a better method.