Breakage

sorry the reply is so late. Firstly, please do not re dye it. If you were using box dyes, it was probably one with some coating agent such as silicone. these make your hair feel silky and healthy but they just coat the problems your hair might have underneath. Peroxide will only make the problem worse.

since your new growth is breaking off, the more likely answer is that this is due to a health problem. Either vitamin deficiency or some other internal issue. I would get checked out by a doctor and have a blood test to check everything is ok. once that is cleared, then i would try silicone free hair products and try to rebuild the condition of your hair with some reconstructors and moisture masks.

You should give some serious break/ stop treating chemicals to your hair. Let it repair by itself. You dont have to Dye your hair regularly.

I need serious help
So I’ve been coloring my hair professionally for years - dark brown
One year ago was the last time I had it done, I noticed a lot of my hair was starting to fall out so decided not to use heat or dye it again
It has been one year and within the last few months the new growth at my temples has started to break off,  the whole top layer seems to be completely damaged even tho I haven’t used heat or Colored it in a year
I’m afraid to wash it, it seems like every day it gets worse and now I have a frizzy mess of breakage in the front- my natural hair is fine and thin
My hair is to my shoulders and has been trimmed regularly
It seems like the breakage is where my new hair meets the old dye
Should I just recolour it? It seems like it was healthier then.

Some of the common reasons for hair breakage are:
1.Lack of moisture in the hair
2.Washing hair with saltwater
3.Excessive use of dryer or strutter on hair
hair dyes
4.Using cotton cushions
5.Using the same towels to wipe the body and hair

Following are some home remedies that will help you:

Aloe Vera

Aloe Vera is known for its miraculous properties on skin and hair. It contains antifungal, anti-inflammatory, and postoperative properties that keep the hair free from dandruff and prevent hair from breaking. Aloe vera also balances the pH of your hair because its pH is similar to the hair pH.

Argon oil

Argon oil is a good source of vitamin A, vitamin C, and vitamin E. It also contains the properties of many antioxidants that protect your hair from getting cracked and spoiled. There are also linoleic acids and omega-6 fatty acids that provide moisture to the hair.

Onion juice

Onion contains abundant sulfur which is useful in increasing hair growth in hair. Not only does it prevent your hair from falling, but also makes them strong and healthy. In addition to this, there are antifungal properties which protect hair from being rusted and also remove dandruff.