Funny, a few things I’ve noticed in your routine have left me with many questions. You mention liking layers of hydration but the majority are glycerin or water based and of the lightest textures, so yes technically you’re hydrating but you’re not really utilising the hydrating heavyweight Hyaluronic Acid or anything of substance. I’d definitely try incorporating the HL in there somewhere. The tatcha really is more of a makeup finishing spray imo than a hydrating spray which is what I’d utilise it for and if you’re feeling dehydrated during day it’ll make for a good top up.
I asked if you were of Asian descent as it can explain your dehydration at such an early age (genetically SEA have a compromised moisture barrier). Otherwise, at your age and only hormonal acne (which isn’t really a skin issue as it’s more hormone related) is a bit of an odd thing to have.
I’m not surprised you’ve seen little improvement with TO, the Niacinamide is formulated for breakout inhibition in the acneic (not the hormonal sort as that is so geared up into hormones, at best it can help calm the situation down once it erupts) where HS Shark Sauce really is made with that Asian ideal of skin brightening and melanin inhibition so they both play to different strengths form Niacinamide. So I think it makes sense to finish up TO and return to Shark Sauce. I have yet to hear anyone say anything nice about TO Lactic Acid 10%, it’s just a dud in their lineup. I suspect the same of the Alpha Arbutin and there will be AB version that are better formulated for what you’re looking for with it, the brightening. The retinoid is again something you wouldn’t find use out of unless you suffer with continual acne/breakouts (rather than hormonal although it may help with how severe this is when it comes but you’d need to use it more often than occasionally, this goes for the Niacinamide too).
Basically you’ve got all the interesting stuff in your stash but it isn’t necessarily ideal for you. You appear to be using a boat load of product (most of which feels superfluous) and I’m not really sure what you’re expecting to achieve, I’m half suspecting your dehydration is on account of excessive product use more than anything else.
Also, curious what you’ve done about the hormonal acne outside of personal skincare, as this is such a difficult thing to tackle with just skincare, it really needs to be a broad approach that may or may not involve prescription medication.
Wrt stash, in all honesty I think you can sell the majority of it. At your age and your specific issues I see no need for the majority of them, some will be too heavy others are just not going to do anything for you unless you have the severely parched skin of a 45+ yo. I can go through it one by one but the general rule, the pricier stuff is best sold on as you just won’t see any improvements from it in relation to the investment.
Are you liking the Melano CC as this is the perfect type of Vit C for you, it’s good for Post Inflammatory Hyperpigmentation and brightening? You’ve got a few other Vit C in your stash and considering the rapid oxidisation consider selling some especially the DE to me, please 
. The HS Lemon Shark is MAP so should stay good for a bit. Someone on here was quite happily using the SC Serum 10 but could no longer afford it, they may want to buy it off you.
So wrt to taking down the steps in your routine, I’d suggest finishing up the floral watery type products currently in use like the MC Raw Sauce, OM revitalising beauty booster, OM serenity beauty booster, and repurposing the Tatcha as described above and not rely on them too heavily in your routine. I’m not against floral waters, they can be very nice and soothing but in terms of performing skincare they really don’t have much impact. If you’re severely dehydrated I’d say HL in the AM and HL Premium in the PM. Are you sheetmasking nightly, that feels very excessive too?
Acid toning- similar issues you have a whole load of high end acids that I wouldn’t be reccing anyone unless they had specific issues with the more common and cheaper acids and had no choice but to use those. What have you tried so far in terms of acids and what has it been doing for you? Are you also doing this on the daily?
Eye Cream- unless your skin profile is decidedly different or more sensitive in that area at 22 I really see no point of an eye cream and if you insist on using one at least till the age of about 28 don’t spend a lot of money on it. All you want is a bit of moisturisation, far more important is to wear daily SPF which appears to be completely absent on your routine.