How do i know if it's overbleached

I just started going lighter and used bleach on my roots.  Left it on for only 35 minutes.  That was probably 5 minutes too long for the first parted section because it went very light.  I used my hair color on the root for only 5 minutes because I thought the bleach processed it.  It didn't go darker.  I tried again with a darker shade for another 5 minutes and it still didn't go darker.  Finally, I bought a med. brown and dyed it again for 8 minutes and it still didn't go darker.  Is my hair damaged and not taking color or is it still "virgin" and the color isn't staying on long enough.  At this point, I'm terrified to try the longer processing.

It doesn't feel bad.  It isn't rubbery.  It hasn't broken.  What do you think I should do next?  Besides part my hair on the other side.