Welcome!
First, like was mentioned already, think of big quantities as "bugging in" sizes, ie, 1 gallon of water/person/day. No way you want to carry 3 or 4 gallons of water if you bug out. Rather, I have something to treat water in my bag. Now, yeah, you're in Sacramento so your water access is rather limited if you leave home. Head east, hit the mountains, find a nice stream. I've also found that about 2-3 quarts/day is about when I hike, so really, if you bug out you might be OK with 1.5 gallons for 3 days. A lot of my camping is in the Sierras, being from CA myself.

Personally, my house supplies can probably get me through a week. My BOB can get me through 3-4 days of food/shelter, but only about a day of water (Michigan is much wetter).

Don't forget, just cuz you bug out, you don't have to CARRY everything. A wagon or something else with wheels can really help with the load distribution. Or you can grab everything and toss it into your car.

Also, have a plan for where you are going, and then pack accordingly!

As for your FAK, well, I'm a long time EMT. I wouldn't personally pack anything that goes beyond BLS. Less chances of lawsuits, plus if you initiate higher level care, then you can legally only turn over care to someone of RN or higher authority. That means when the EMTs finally show up, you have to go too! Finally, it'll get expensive replacing things with an expiration date. Gauze really doesn't go bad, y'know? Of course that means someone might die, but let's face it, if they're that bad, you're probably endangering yourself and others by taking a higher level of care than the situation can safely allow. As the prehospital folks learn, SCENE SAFETY FIRST. Triage yourself- if you can't be safe, you shouldn't be there.

Hope it's a good start. Welcom!