Will my hair ever grow?

My hair is heat damaged. Like really badly. I never used to used heat protector and I straightened my hair every day for 3 years, now my hair is really bad. My sister does exactly the same but her hair grows every day and is WAAAAAAAAY longer than mine and shes the one that told me heat protector isn't important and i believed her because her hair is actually amazing. My hair is shoulder length but I always cut it to a bob to get rid of split ends but they always come back. I have stopped straightening my hair for 2 months now (that's when i realized i hadn't been straightening it correctly) and I always take take of my hair but people are telling me its never going to grow because its too damaged. I'm really scared and i want my hair to grow but people keep scaring me. So can someone tell me if my hair will grow longer than shoulder length, how long it will take to grow longer, if cutting my split ends off is helping because they always keep reappearing and what I should do to make my hair healthier. P.S. I have very curly afro hair and I have dyed it once. Thanks