1. "Bitching" about things is one of the few ways we get things done as ordinary citizens in this country. Protests, boycotts, even voting are forms of political speech. If we see a wrong in the world we should speak up about it. It may seem like a waste of time, and in the short-term likely is, but if enough voices do speak up they can sway things. If there were a mass movement we could probably easily get the pharma companies to send out more just for the PR, and despite the cynical motivations it'd result in more folk getting vaccinated. Not likely to happen though, in a country torn between "me first" and "I'm not taking that thing".
2. You can absolutely look out for yourself and your loved ones. As I said before, "I got mine" and/or "looking out for #1" are very common political philosophies, especially in the US. But don't also be offended when someone points out that it's what you're doing and that they think it's wrong. You don't need to justify it, nobody's the villain in their own story and we all do mental gymnastics in our heads to tell ourselves we're either not wrong about things or that we're less wrong than others.
I just think it's worth taking a moment to reflect that when the chips are down most people virtue signaling about how much their hearts bleed for the less fortunate in the world during the good times are just as myopic and selfish as the average Trump voter. I'm not sure being prickly and defensive about it is better than owning it (or doing both).