slightly sticky gummy hair-any way to fix

I have thin hair, and have been dying it for over 25 yrs. NEVER a problem....until now.

I've been using Garnier color for the last yr. I like that it covers my very resistant gray hairs adn the conditioner smells like heaven! My hair grows really fast so I am usually touching up my roots every 3-4 weeks (a good inch or so of growth). and I only color the roots, then swirl it thru my hair to refresh for a few minutes then wash it out. As per their instructions.

 A couple of weeks the drugstore was out, so I bought Clairol nice and easy, figuring since I only do the roots, it would be ok..but it wasnt! It was not NICE! and now I'm in trouble. There is a 3 inch section of the middle of my hair, about 2 inches from the roots taht is slightly gummy/sticky feeling. It almost feels like it has too much product on it-but doesn't.  And its ONLY  that section of hair, the ends are fine-so it looks like  band of dirty hair with clean roots and ends....

HELP!!! LOL I do NOT want to get a crew cut, to just cut off this bad part of my hair. My hair is shoulder length now. Is there anything I can do to strengthen the strands or close the cuticles or ??????

thanks in advance!