Let me address your questions and then we'll come up with an attack plan.
"Side questions: I tried vacuum manually to get the bottom cloudy stuff up, but seems like it just sends it straight to my big filter and clogs up so quickly. Is there a way to vacuum out to the yard? I can't see how putting all that back in my system is helping? Feels like a loosing battle"
If you have a setting on the dial valve on top of the filter labeled "waste" or "drain" then yes, you could theoretically vacuum the pool and have the water bypass the filter. There is one major drawback to that (and some minor ones). The major drawback is unless you have a main drain in the pool, the water level would fall too low for the skimmer to pull water into the pump and filter. I know it's gonna be a hassle and a lot of work, but the least expensive option is to vacuum to the filter and backwash when the pressure tells you to.
"and if needed ( raining) I will toss in some granules in the skimmer or just in the pool"
You should ever put chlorine granules in the skimmer or directly into the pool. Tossing them directly into the pool could damage/fade the plaster. Always dissolve the granules in a bucket of water and pour that into the pool in front of a return.
This would be my attack plan going forward:
You have a lot of algae and maybe other organics in the pool. So it needs to be super chlorinated. And that super chlorination needs to be maintained. Ideally the pump should run continuously throughout this process. Realistically, the pump may not be able to run through the night without making the pressure in the filter so high it needs to be backwashed. You will have to make that determination.
Before you get the new kit:
We will use the chlorine reading the test strips give you.
The shock level for a 16k pool is 16 ppm. So take a new chlorine reading and subtract the number you get from 16. That's how much you will need to raise the chlorine level in the water.
3oz of 68% cal-hypo should raise the chlorine level of 16000 gal of water by 1 ppm. So take the number you got when you subtracted the chlorine reading from 16 and multiply that number by 3. That will give you the total ounces of shock needed to bring the chlorine level to 16 ppm(remember to dissolve the shock before adding it to the pool).
Then let the filter run but be sure to backwash it when the pressure reaches that point. At the end of 3 to 4 hours take another chlorine reading. Subtract that number from 16 and repeat the process outlined above. You need to do this every 3-4 hours (if possible) until you go to bed. In the evening before the sun goes down, take the final chlorine reading for the day and bring the level up to 16 ppm. If the filter will go without needing to be backwashed during bedtime, let it run. Otherwise let it run until your ready for bed and shut the pump down. Start it up in the morning with a new chlorine reading.
At least once a day you should vacuum the pool. Brush the pool bottom and walls once a day, preferably in the evening so whatever is suspended will have a chance to fallout before the next vacuum.
As the algae and contaminates are killed, you notice that the amount of chlorine you need to add to keep the level at 16 ppm is less and less. And the daily vacuuming will clear the water.
When the pool holds the chlorine level overnight (within.5 - 1 ppm) and the water is clear and the combined chlorine level is 1 ppm or less, you are done.
After you get the new kit:
Use the 10ml sample to test for chlorine. This will give you readings in increments of .5 ppm and that's all we need.
I would also look for a replacement bottle of the R-0871 titrating agent cause you will probably use a lot.
After the pool is clear we will look at the other things like total alkalinity, stabilizer and because the pool is plaster the calcium hardness is crucial.
Let me know if you have any questions.