I know a little something about the kind of obsessive behavior inherent to consumption purity as an OCD person. Consumption purity is a rabbit hole of neverending torture and despair. By all means, try to exercise your ethical obligations to some extent but please don't think the world's problems are on your shoulders. You are not Atlas. There is no ethical consumption under capitalism. There's a line where this crosses into obsession. By the same token, it would due to drop puritanical consumption rhetoric altogether. It's not helping to reform the system but instead just shames people for being in a body and living in a corrupt system. We can talk about the antithesis of what ethical role individuals play but we first must internalize the thesis of the overwhelming majority power of the system if we're ever to be able to synthesize the two.
Cheat code: If you have to change your buying habits, it's probably not going to have much effect. In fact, it just serves capitalism. There will always be a corporation willing to profit off of any level of consumption purity, casual or obsessive.