Railcards and Benefits For Hearing Impaired Students

Hi, I'm a Y11 going into sixth form in September, and I was wondering if I am entitled to a Disabled Persons Railcard. The sixth form I want to go to is a little far from where I live, so I would need to I would need to take a train daily. I was born completely deaf in my left ear, and used a CROS hearing aid during Y9. My hearing in my right ear is otherwise fine. I'm also not sure if a Disabled Persons Railcard would be a better choice for me that 16-17 one, since I'll turn 18 before Y13 Christmas.

I get extra time and potentially a separate room in exams if it means anything

I am not too clued up on the requirements for a Disabled Persons Railcard but a quick google search indicates that this railcard gives you 1/3 off rail fares. The 16-17 saver gives you 1/2 off, which is a considerably better discount and so it will probably be more economical for you to get that one first and use it for as long as you can before switching to the Disabled Persons Railcard (or the 16-25 railcard, which offers the same discount as the Disabled Persons Railcard).
In the end, you can do the maths on this yourself and figure out what will be the most economical option for you. That's what I did when I was figuring out railcards and what type of ticket (individual, season ticket, etc) to buy when I was in sixth form