I feel your pain Minamyna, I am sure you heard the old saying about not crying over spilled milk? Now you know what it meant. If it's any consultation, I can assure you that every person on this board has thrown away their share of cheese and started over.
Most cultures have dosing instructions that look like "1-5 Gal, use 1/4 tsp, 5-12 gal, use 1/2 tsp" This isn't exactly doubling. Bacteria grows exponentially so it just need the right seed amount to begin. Rennet and lipase are enzymes and you can double them (but watch out for double strength rennets). Same goes for Calcium Chloride which is a mineral. BUT when you put lipase, Calcium Chloride or Rennet in water, there is no need to keep doubling the water. The reason for the water is simply to allow it to distribute evenly all over your vat or pot. It won't dilute your milk strength - the water will eventually become part of your whey.
How do you cook it? Turn on the heat? Wash the curd? (remove some whey and replace it with warm water until you get to the right temp). Washing and cooling takes a bit of practice. not every recipe allows for washing but washing does give you much more control because every time you take whey out and mix some warm water (say, 130-140F) in, you can take a temp reading and see how long it takes you to raise the temperature so you can time it perfectly and easily by repeating the wash more or less often in your half hour (or whatever the recipe calls for)
I would leave the pH meter alone for now. Learn to feel the whey and curds, to smell them and look at them. The pH meter can drive you nuts and steer you wrong at this point.
A proper Parmesan should have lipase in it. It breaks down fats and proteins at the late part of the aging, giving the cheese its famous sharp flavor
Some brands of non-homogenized milk also offer it in lowfat variety. I wouldn't go crazy, since most of the fat is on the top of the jug, just spoon it off, reseal the jug and shake it. Done.
As for forgetting the CalCl - best practice will be to print a checklist every time you make cheese. It should be super simple, like:
-WARM milk to 88F
-ADD:
+ 1/4tsp MM100 Mesophilic
+ 1/8 tsp Geo 15
+1/8 P. Candidum VS
- RIPEN 45 minutes
You get the idea... Hang it on your fridge when you make the cheese, get a sharpie and cross every item when you do it. You will never miss another item again, ever - guaranteed.
If you write comments next to the items such as the time started/ended, type of milk, overshooting or undershooting temp. etc you will have a draft of a proper log that you can copy to a clean file and keep so that a few months down the road, when you taste the cheese you can trace successes and failures of cheese characteristics to specific things you have done.
Lastly, if you have over-ripened your milk by adding too much cultures (you said you doubled everything) and by cooking for too long (45 minutes? I assume too long for your recipe?) than you have possibly created acidity that would turn out hard, dry, chalky and non-melting cheese. Even if it looks great, you won't know about it until you crack open the cheese months from now. Throwing away the batch probably saved you a disappointing surprise in the future. These losses are harder because they follow months of caring for the cheese.
Do over...