ok.. a few things. Do u have to blow dry? this will make your hair frizzy and make it hard to straighten. When its wet.. let it dry by itself. Then add some anti frizz serum and straighten small sections at a time.

No straightening every day wont wreck your hair, tho it may make it a little more fragile.. or stringy. Just do a treatment in your hair every 2 weeks and looks for a heat protecting balm or spray for ur hair before u straighten.

No there is no need to get a GHD straightner.