What is the best shampoo for hair that is severely damaged due to coloring?

I have colored and highlighted my hair a few times too many in the last year and now, whenever I shampoo and condition it, when I get out of the shower it is almost impossible to comb through. I have very bad breakage which you can see on the top of my head, much more than I've ever noticed on anyone else. When I brush my hair, huge amounts of breakage come off on the brush. I mean, I know that almost everyone has hair that breaks a bit when brushing and such but mine comes out in small handfuls. I need to find a shampoo and conditioner that will make my hair softer and healther so I can actually comb through it. Please help!