A good employer should look beyond the condition and concentrate on the applicants credentials and qualities as a person, more so in the position you are applying for Ebony! I do accept that this isn't always the case with employers, and through ignorance and lack of training will see diabetes as a obstacle.
I don't think I have ever been discriminated when applying for a job, and usually get to the interview stage where I can explain my diabetes control, I've had 10 jobs both part/full time since diagnosis so don't think diabetes has held me back.
Good luck with your application!
Nigel