The best thing about hair is that it grows. Hopefully, your new growth is coming in healthy. I've had low thyroid and taken medication for 30+ years.

As earlier posters have suggested, it's good to read and learn. It's also important to learn your hair properties. It helps you choose ingredients/products and assists folks in helping you. Here's a link to help With all the damage from the coloring, it's most likely that your hair is porous.

While it's difficult to restore really damaged hair, it may be possible for you to improve it a bit. Learning how to handle your hair is really important to prevent further damage with the new growth.
3a (Corkicelli), highlighted, fine, low porosity

HGs: Anything Sevi; Curly Kinks Satin Roots, Curlycue ReNew and Coil Jam; homemade FSG and okra gel; soap bars; UFD Curly Magic; Botanical Spirits Jellies, CJ Repair Me, Aloe Fix