I’m just nervous about the interview panel asking further questions regarding my PTSD especially. legally they’re not allowed to ask about your disability.
The downside to that is that if it’s an obvious disability they won’t know or potentially even think that adaptation can be made and out of ignorance may simply not give someone a job on the basis they don’t see how it can be done.
Bear in mind that the pannel won’t be told your disability status, just that you have applied under the disability confident scheme. If your disability is an invisible one, they will not have any idea what it is.
In my case it becomes somewhat obvious when I walk into an interview with either a cane or a guide dog 
but that aside, I always bring the subject of my disability up myself and talk about the adaptations that will be needed/are available. For the interview last October I took along a laptop with a screenreader installed and a braille display. They were happy not to need to see them but were also keen to listen to what I had to say, and as I said, I was offered the job.
Some companies will discriminate, but I think it’s also important not to just assume you are being discriminated against if you don’t get the job. It’s equally possible that you just weren’t the best candidate for that particular job. Unless the discrimination happens openly, I would just put it down to interview experience.
I have not been offered jobs just because there were better candidates, I have also been openly discriminated against (interview offer withdrawn because of my VI). In the former cases I just move on and put it down to one of those things. There is nothing positive to be gained by telling yourself it was discrimination.
In the latter cases I genuinely believe that if they can be that discriminatory at interview they are very likely not the kind of company I would want to stay working for anyway.