I have exactly one word of advice: Medicate.

I was suicidal, to the point of making quite efficient, detailed plans that I simply couldn't be bothered to actually implement.

A couple of more words... the early stages of medication are actually associated with increased suicide risk. You allude to the reason here. If functionality is increased to the level of actually being able to execute plans before the 'wanting to actually live' catches up then bad things are more likely to happen. This is where therapy becomes critical.