That would also make you bleed to death, which is also more difficult, stabbing yourself requires a death with the loss of blood which would put you in a lot of pain, ok the other hand with blood clots you would need to go through as much pain and you could also die that way, you just need to cut your blood circulation near a major vain, another pain free method would be an overdose, over dose is m e h, if you don’t take enough pills you won’t die you’d just either collapse, be high on meds, or just nothing would happen, so it’s a 50/50 thing, it also depends on the medication you use, an insomnia prescription would be your best bet, I tried using it before and I didn’t take enough so I was just sleeping for a long time. Another method would be suffocation, it’s a simple solution but you need sheer will, it’s best if another person helps you with that