Introductions - Newbie with hair issues!

I used to have hair down to my waist - it was thick, shiney and beautiful. It rarely had split ends, because I had it trimmed routinely. I had my hair highlighted while it was this long, each time my re-growth became too much. :) I slowly started getting it cut shorter and shorter over the past year, since my daughter was born (Jan 6th, 08'), until it reached above my shoulders and 'stacked' in the back with longer hair surrounding my face. Over this past year, my ignorant mother-in-law who used to do hair, has been highlighting my hair and cutting it. About 6 months ago, my hair was getting too blonde and she colored my entire head for the first time in my life, trying to match my real color, which is a light brown. It looked terrible - dull and NOT a natural color - it didn't match my natural color at all. After the all over color, she added some highlights back in right away. This is where all my troubles began. I can hardly get a pick through my hair when it's partially dry after washing it and it's completely unrully. I have tried everything: moisturing shampoos/conditioners, fortifying shampoos/conditions and masks, leave in conditioners on top of the regular wash-out conditioner, etc. I leave a Biolage fortifying mask on for 45 minutes before rinsing out at least once per week and my hair is still extremely dry. I feel like it's ruined forever and it's soooo depressing. I used to be known for my long, gorgeous hair, and now it's crap. :( I've also been letting it air dry and not using a flat iron on it for a month, to help it out, but I can't always avoid those things. It looks better after flat ironing. Oh, and when I say it's extremely dry, let me explain: The ends tend to curl, are split, it feels like straw and also hair breaks off when I use the pick or my fingers to comb it. I don't know anything about coloring hair, but what it looks like to me and what a hairdresser has told me, it looks like it's been over processed with the bleach.