I need help fixing my hair! Please!?

A year ago at this time I had gotten highlights in my hair, and i think my hair dresser left them in for too long, and when i left my hair was falling out, I first thought it was the cotton but it was actually the blonde in my hair where it was bleached from the highlights. The hair was exactly like those little thin white elastics, say if you rip your jeans and the stuff that binds then together(I hope someone knows what im talking about), and it would break that easily. I didnt touch my hair, I hardly ever style it with blow dryer or straightener. I have gotten my hair trimmed 3 times since. now, my hair has been very rough and stubborn. When i wash my hair and say I do style it, it goes flat almost instantly. just after i wash it and its wet, its almost impossible to brush through, (not as bad as steel wool, but some what of a comparison), now its a little bit better but still hard to brush through, and my hair goes so flat. I just want my hair back to its normal softness. and My hair has always been kind of fine, It usually goes flat, any tips on how to get better volume ? Thank you so much for all your help, Im desperate!