The rule of 3s is heavily weighted for the 1st 72 hrs. Experience has shown that if people can survive that long, most will likely get to help; or, help will get to them (YMMV). Likewise, weigh your BLS guidelines for prioritizing acquisitions. Primary survey - ABC, start an IV. // VS // Secondary Survey. That translates into A: Mouth shields, J-tubes, B: tourniquets, topical clotting agents, field dressings, cravats, ace wraps, tape C: ...
... C: Here you may have to make a major adjustment to civilian life. What saves the most lives on the battlefield are IV fluids. Every member of an SF A-team carries a 1L bag of Ringers Lactate, administration set, and can start an IV. As a civilian you'd need a prescription for that. The alternative for someone who can't take fluids PO is
RECTOCLYSIS. You'll need to obtain/construct apparatus to reliably deliver the fluids without you having to remain conscious for continued self administration; or, having to stay with someone else. The fluid containers will have to be durable enough to withstand the temperature extremes where they'll be stored. You'll need the capability to both quickly heat and cool the fluids to near body temperature so you don't induce either hyper- or hypothermia. Check body temperature elsewhere so you're not just reading the fluid temperature.
VS: Equipment with which to evaluate your critical management. packed so that it won't break or rust out.
Those things are what saves lives. Stock and configure kits in order of priority for not only your use; but, for others to use on you. That latter aspect may be what saves your life. CPR mouth shields can be a deciding factor in whether or not someone will even try to resuscitate you. Short, concise instruction sheets can help others, even if as only a memory aid, to become engaged in helping. Redundant kits are good backup and contingency planning. They should be easier to maintain in a vehicle or storm shelter.
To take advantage of your familiarity with military supplies, shop online surplus stores. It can be surprising what's out there. Supplies don't have to be perfect to keep you alive for those first 72 hours. After you've accomplished the above, we can get into the secondary survey - non-critical management and palliative care. No point in passing pills and putting on band aids for dead people. Later, perhaps some preventive medicine (e.g. if you know a potential disaster is looming like tornado weather, hurricane, ice storm...etc, - stay off anticoagulants like NSAIDS and ETOH). It might seem like the prevention aspects should come first; but, those things are harder to predict and it's harder to change those behaviors in people.
I'm not trying to be all inclusive here. This doesn't even come up to the level of hip-pocket training, it's just an overview ... food for thought. Feel free to ask questions. I still browse the laundry lists 'cause you never know where you'll find a gem.