Purely as a thought experiment, this is mostly just vacuous logic. Sure, you can kill yourself, or kill everything you love or hate, or make sacrifices that are probably infinitely greater than the suffering itself (you could choose to stop caring about human suffering, most would much rather suffer than do that).
In practice however this is even worse than vacuous, it's just wrong and insane. You can't choose to not be schizophrenic, physical and psychological pain aren't two neatly distinct categories, saying it's "a choice" is just drawing a completely arbitrary border on where choice starts, and no shit people get angry at you because unless you heavily qualify this kind of statement further, anyone would think you're doing the purest form of bootstrap victim blaming argument possible. Anyone would think of that one time they suffered the most in their lives and you're saying "you chose that, that's on you".
If I try to be as charitable as I possibly can, I would assume this is an attempt at criticizing self-pity, highlighting that we are often our biggest obstacles to healing and that will plays a greater part in our agency than we recognize. I'd agree with all of that, but that's being really charitable, I don't think your statement makes that case at all.