I'm sorry what you had to go through, but no that is absolutely terrible advice. You can't just blanket state you'll recover from all drug overdoses without medical intervention just fine. For example, all of the SSRI antidepressant pills, those will give you serotonin syndrome, which at high severity will need medical intervention. Painkillers are absolutely terrible to OD on, and can lead to various damage and even failure of various organs. Not to mention for all drugs in general, you'll do more wear and tear to your liver, kidney and maybe even other organs if you simply leave your body to try to deal with the OD on its own instead of looking for medical intervention.
If you want to CTB via drug overdose, do your research! Seriously I can't stress that enough. Also even for the drugs that you actually have a chance to CTB on, many people greatly underestimate how much of said drug you need for any decent chance of CTBing. Only the stupidly powerful stuff like Fentanyl, Carfentanil, Etonitazene (and maybe Isotonitazene) is it possible to CTB less than 1 gram on. Even the glorified Nembutal/Pentobarbital is recommended to take 10g minimum for the majority of people to CTB from.