i hope its just chemical damage

[marcus84]

im naturaly dark like black but for a long time i dyed it blonde it started to get brittle and brake so i cut it shoter and dyed it black since then its been falling out by the root the coulour is not my natral and has a reddish tint to it my natral is thick whats not been cut off is thin im 28 and iv alwsys had a great head of hair do i shave it will it grow back or am i really looseing my hair its coming out in the bath and on my pillow its also very easy to pull i have a widows peak and shaved that part of whitch can be hidden by my fringe that part apears to be growing back normally iv also noticed my hair has become alot more oily is that a good thing or bad any advise id be really grestfull for also please excuse bad spelling and grammer im dislexic thanks marcus