I am the QUEEN of hair repair. As many know I have platinum blonde hair and it looks great, but only because of how well I take care of it after a "chemical haircut" that happened years ago (basically all my hair broke off after a rather harsh couple days)
Heres what you need:
Protein Based conditioner and shampoo (I like Bedhead Dumb Blonde)
Protein Based Deep conditioner (I like Joico K-Pack)
Moisturizing Shampoo and Deep Conditioner (I like Redken All Soft Heavy Cream I think its called)
Heat Protector for styling ( I like Artecs Hot styles ironing cream)
A wide tooth comb
Leave in conditioner (I like Redken Anti-snap)
Get a trim first to get any dead ends off
Alternate between moisturizing shampoo and conditioner and protein shampoo conditioner
Try to lay off shampooing your hair every day, I only wash my hair at most twice a week, and it made a HUGE difference. After about a week your scalp adjusts and produces less oil so you won't look greasy, but if you can't do that make sure you dont shampoo every single day.
Use either or deep conditioner at least once a week
Dont use protein all the time it will strengthen your hair but too much will make it brittle, you need to add moisture as well.
Use a wide tooth comb to GENTLY comb the conditioner through your hair to evenly coat every strand. After you get out of the shower only use a wide tooth comb, your hair is the weakest when it is wet.
DO NOT towel dry your hair and try not to wrap it up in a towel on top of your head, this pulls the hair making it likely to snap. Instead blot excess moisture with a towel, and wrap the towel around your head and hair leaving it down if that makes sense.
Try not to blow dry your hair if you straighten with an iron, I wash my hair the night before, let it dry, and then straighten in the morning. This will take A LOT of stress off your hair.
USE THERMAL PROTECTION FOR HEAT STYLING!!! If you straighten, it is better to straighten small sections at a time (an inch or two) slower than to run it over bigger sections quickly because chances are you are going to do the same sections over and over.
Dont put your hair in a pony tail the same place every day, especially when you go to sleep, it is better to put it in a braid or a really loose bun.
If your really serious a satin pillow case helps to minimize damage.
I hope that helps! It might be extreme for what you need but for anyone else looking to greatly improve their hair, this is the way to go. I would not have one strand of hair if I didnt do this