Help please i think it's dying???

Okay guys I really need help I have 8 to 10 week old Autoflower I'm not too for sure as my records were lost but it sprouted around the 28th of October or 21st it was stunted for about 2 weeks as it stayed very very small well now as it is 8 weeks to 9 weeks old I was having some issues out of it so I flushed it I am in Fox Farm ocean forest soil I am using the fox farm Trio I've been scared of the nutrients as I was told the soil would hold its weight for about the first month so I've been given nutrients off and on slowly my pH meter was messed up as I found this out later and have been having pH issues as when I use tap water that is set for 48 hours with calmag and 1/3 strength nutrients the pH comes out around 5.5 but when I put it in it was like 6.5 well now I immediately pulled it out of my closet that had my Gixxer 1000 watt LED light and I put it underneath my Mars ts600 with my two other photo. Well upon looking it's like almost every other Leaf is starting to Yellow like it's Autumn mean off not so much like a nutrient deficiency of nitrogen but bright yellow almost red on some of them I still have lots of white hairs but the plan is really bushy I am afraid to defoliate tomorrow I'm starting half strength nutes for Bloom as I just flushed it the past 2 weeks I let it completely dry out until the leaf showed signs of underwater then I watered with straight pH water at 7.7 in which it came out at 6.4 6 point five so again I'm afraid it's dying as it is been almost nine weeks to 10 weeks old in which the breeder said it should be done it is zkittlez Autoflower under again a Mars ts600 in a 4 x 4 closet with fan circulation great air flow 80 degrees 50% humidity

Your plant isn't dieing, it has a deficiency. Do not defoliate! Your leaves are yellowing because sugars are being taken from them as the plant corrects the deficiency itself. Removing leaves before the deficiency is corrected will only move the plants correction measures to whatever leaves are left.

Oh no i defoliated today ive tried researching everything i can't find what it is deficient???

Ya don't trim autos..especially during flowering, they tend to over react and take so much time to get them back on track

That's what i thought a few guys online said my play waa to bushy and needed defoliated...I'm a dumb as i knew this read it over and over still can't fix my girl tho???

Leaves grow buds. Removing them leads to less bud production. Don't love your plants to death.

Does it look like it's deficient or autumning off??? I'm really scared it's dying!!!

There is no automning off indoors

It's exactly what it seems like as out just keeps progressing and its all over pin to bottom middle inner canopy everywhere...ph is 6.4 in 6.4 runoff. Nutes half strength ff trio. Removed rough looking leaves so i could see any new symptoms...as i am very confused 80 degrees Fahrenheit and 50 percent humidity

What should i do what is this deficiency???

Here's the thing, you either have/had too much of something causing lockouts or too little of something. Too much is usually the culprit.
Defoliating removed your insurance policy and put movement of the issue on the fast track through the plant.
If you were in coco, I could have you back on track in a couple hours. Soil, I could tell you what I would do but then 40 people would tell you why I'm wrong and most of them would be correct.
I run a couple plants a year in soil and it's never a good time for me.

I wish I could offer more help.