I want to start wearing my hair natural but since i straightened it so much some peices are straight
You will need to get rid of the damage by cutting it off, and preventing new damage by creating a healthy hair care regimen.
I suggest you use a protein treatment in order to repair your hair. Aphogee 2 minute reconstructor is a good one. You could reapply it every few weeks. You could also try to manipulate your curl pattern by doing twistouts. Hopefully, that will help your hair to revert back to it's original state. But if those things don't help than you may have no other choice but to gradually cut if off.
You'll probably just have to wait til healthy hair grows in and then cut off the damaged part. You probably won't be able to "rejuvenate" the damaged part, but you could dry by using weekly deep treatments to see if that helps.