Actually, if you asked me to kill you and I did, I'd still get arrested due to anti-euthanasia laws (depending on jurisdiction!)
Using your reasoning, we should happily eat any animal (possibly including human, but animals also commit suicide sometimes) that suicided...
I think death is an inherently ugly thing no matter how you approach it, and given the existence of carnivores and omnivores who are not vultures waiting for food to die before consuming it, I don't think killing in nature for food is avoidable. Pain avoidance is much easier to reason about, however.
Like it or not, we are part of the natural world and its strange rules of engagement. Having just watched a hyena eat a wildebeest alive (someone in the comments here posted it), I have to wonder if humans are not the most "humane" killers-for-sustenance on the planet. The most ethical thing we can do (other than creating meat in a lab such as what Impossible Foods is doing... I'm a fan), IMHO, other than go vegan, is to be as humane as possible about the killing bit, give animals as full a life as we can, even if we intend to eat them towards the end of their lives.
I believe that one day (possibly in the far future), every human will be vegan. I can't say that it's reasonable to expect everyone to be vegan now, though. The French love their cheese, the Germans love their liverwurst and bratwurst, the Italians love their pizza, and the Japanese love their sushi. I am a huge fan of grilled chicken, eggs and sushi (and the VERY occasional burger or bratwurst... I'm ethnically German, btw) and the wide variety of cheeses out there... these things would be extremely hard for me to give up, so my fallback position, for now, is to obtain these things in as humane a way as is possible for me right now.
I commend your veganism, regardless. It is admirable and it is an ideal you have attained in this time and it should be emulated.