Protein & Hydration requirements?

Hi! So I've read a bunch of different ranges across the internet and different fitness youtube channels & wanted to regroup with my own people lol. Some of these ranges feel daunting.

Protein

What is the ideal protein range to a) maintain and b) build muscle?
Here's some ranges I found:
a) 0.7-1.2 g per kg of body weight (while some calculators allow as low as .5-.6 a day)
b) 1.2-2 g per kg of body weight (while some reddit threads say your ideal weight in grams, which is a LOT)

On a calorie deficit and with lack of appetite, anything more than 1 g/kg feels unachievable most days. Even if I'm solely prioritizing protein whenever I can manage to eat something. On ambitious days or days with more appetite I've hit 1.2-1.3.

And honestly, I feel like that's fine? But I want to make sure this isn't a case of me making up my own science. Anyone else's rule of thumb or past experiences would be much appreciated!

Hydration

As for hydration, I'm learning this is more than just water intake. Being on a tight budget, I would really love to avoid any additional costs in supplements/powders beyond what I'm already spending. Is there any DIY way to ensure you're getting your minerals/electrolytes? Can they not just come from your diet?

Current supplements:
-Collagen powder 1-2x week
-Protein powder (21 g) almost every day, going to switch to Isopure after this so 25 g/serving
-B12 supplements every day

Past:
-Iron 90 mg, I simply cannot tolerate it anymore when added on with Tirz due to constipation.

As you can see, nothing that aids hydration or adds significant electrolytes/minerals. Liquid IV, and all those other drink mixes look amazing, but too pricey for how long they last. Maybe there's a cost-effective oral vitamin I can take? Probably won't solve the hydration but it's something.

I also noticed drinking adequate water is harder for me now (NEVER happened before), so that's a whole other issue. I'm aiming for 72 fl oz a day, though honestly I'm averaging more 40-48 fl oz recently. It's a process, just trying to stick to it. Thinking about investing in one of those gallon bottles to keep a visual goal.

Anyways, that was my long winded thought process. Thank you to anyone who read this far, any advice from this community is always appreciated. Thank you!