Please help me with my really damaged hair!!

       Hi Im 20 years old & Im a person of mixed race (White and Black) and my hair was naturally curly, wavy, silky form birth. I really didnt know how to take care of my hair,and I didnt know what kinds of things I should and shouldn't put in or on my hair. So I never did any thing but wake up take a shower and where my hair down and it would be down my back (really curly,silky and wavy) or in a hair tie. Eventually I got used to it and I really like it, People would compliment me on my hair. Then I turned 14 and became a teenager and I started trying to do different things with my hair to try and change it up like, I put a relaxer in my hair to straighten it (which I should of never done) At that time I didnt know all I had to do was blowdry it straight and then used a flat iron. So Basically from then on my hair changed it never was back to normal, It got damaged like frizzy, puffy, dry, it wasn't silky anymore, and the curliness was completly gone. Ive tried everything to get my hair normal again, I just dont know what to do. Is there someone who could probably help me, are there and shampoos or conditioners I should try. What products should I try to use. What  could help my hair! Help Please