I don't know if you tie you hair often, but it's best to have them down for as much time as you can stand. Try to avoid blow-drying and flat-ironing (again, don'tknow if you are doing it).
I put coconut oil on my hair before I go out in the sun (I'll have to wash it anyway), and it makes them very soft, after washing; don't know how much it could help with breakage tho.
Vitamins from the B group are useful to strengthen the hair: you could probably try some yeast (like, bread yeast, saccharomices cerevisiae) supplements (I am a nerd, so I don't mind eating a piece of yeast). And a diet too low in fat can somehow affect your hair too.
Garnier fructis is advertised to strengthern the hair. May be you can try it. I like the hair mask, how it leaves the hair, not sure how effective it really is tho