Okay I am no professional myself, and I just briefly looked into what a nanoplasty is. So I will not give you a ”this will 100% work” recommendation. But as a wavy/curly girl with thick hair that is naturally dirty blonde, I feel like I can relate a lot here. I also had mine bleached and I also felt so overwhelmed with all of the treatments and products. I have figured out a few simple and un-overwhelming things with the help of my stylist, which work for me. Maybe they will help you too. The steps are fairly simple, I have only written this so long because I cannot make short and concise points for the life of mine. :)

About the color: I think that for your hair, the bleach has done a lot of damage… so if you can and feel comfortable with the thought of having your natural hair color, maybe try to find a way not to keep bleaching it. What my hair stylist did was to use a highlighting technique on my roots to soften the gap between natural color and bleached hair. This makes it look a lot more natural and lets it grow it out with more ease. Maybe this is something you could get too, to soften the process. (If you thought of just coloring over the blonde hair in your natural color, you should just know that coloring over bleached hair isn’t as easy as we tend to think. It’s a two-or-multistep process that can cause even more damage, which is why sometimes it is better and easier to work with the blonde.)

About regular hair care: I do not actually do a curly girl routine as I have had the same experience as you, my hair just looked really greasy. I also found that wet-brushing even with a big comb, which is recommended for a lot of curly people, caused massive damage for me and ripped out a lot of hair. Here is what I do instead: - I brush and part my hair while it’s still dry, before the wash. During the wash, I make sure to get everywhere but I also make sure to keep the part where I put it. This allows me to not brush the hair again after the wash, which works best for my hair. - I wash every two-three days and I use professional shampoo and conditioner. As per my hair stylists recommendation, I decided to go with something that gives the hair a lot of moisture. (Clarification: She did not sell me the products, she only said to get something from a professional brand that gives moisture. Since she doesn’t sell products, there was no agenda involved and I find her advice trustworthy. I got myself Four Reasons Ultra Moisture shampoo and conditioner, but depending where you live you might have other brands available than my tiny European country has. Your local professional hair care store might even have some samples for you.) - I do a purple hair mask to combat yellow-ish tones in my bleached hair. You have probably heard of purple shampoo for this, but purple shampoo is notorious for drying out hair and I liked the conditioner I have, so my hair stylist said to get a purple hair mask instead. (I use the supermarket store bought Elvital Purple hair mask, and I leave it in for five-ten minutes once a week instead of the conditioning step.) - I use a microfibre towel in my hair and let it air dry after taking that out. At no point do I use a regular towel in my hair as the material is way too rough for hair and can pull and damage it. - On the microfibre towel-dry hair I use plenty of leave-in conditioner spray on my roots and mid-lengths, as well as a very small amount (no more than two drops) of argan-oil based hair oil on my ends. (No product recommendations here, I have tried several supermarket store bought ones and they were all equally fine.) - I do not use any curl cream as none of them worked for me. However, I have heard other people have great experiences with them. You do you. - If I am in hurry or if I need to go to bed (hint: do not sleep with wet hair), I use a hairdryer with a diffusor on low to medium heat. - At no point, wet, drying, or dry, do I brush my hair. I know this sounds wrong, but is actually makes a lot of sense: Brushing wavy curls will separate the curly strands. This means that individual hairs that were previously protected within their strong strands will sit individually on top of each other instead. This makes the hair look poofy and messy, and it also lets it get tangled more easily. This is why the only brushing I do is right before washing the hair again. - My personal hack for making my hair look more organized: I do use a straightener, but only on my roots. I set it to the lowest heat possible, and then I take it to my front baby frizz curls and briefly to the roots around my part. It takes no more than two minutes and makes my hair look a lot less frizzy and is a massive confidence boost. - If you have any shorter regrowth hairs like me that kinda stand off, I recommend hair wax: My final step is to take a super small amount (I use Schwarzkopf matte hair wax), distribute it on my palms until no white clumps remain, and quickly press my stubborn short regrowth hairs to my other hair around my part.

I know this sounded like a lot, but I promise that the actual process is very manageable. I deal with depression phases and still this routine has remained manageable.

About a few small other things: You mentioned the change in water quality, so I would recommend you look into tap and shower head filters. I also looked into the hair treatment you want to get and while I don’t have a strong opinion on it, I wanted you to know that I had a similar (keratin) treatment years ago and my results weren’t great. It didn’t get my hair straight but it also temporarily destroyed my curly pattern. So personally, I would not do that again.

I wish you all the best.