Dyscalculia and IGCSEs - What to do?

For context, I am in my second year of IB studies, and I was diagnosed with autism spectrum disorder at the age of fifteen. However, I have good reason to believe that I may also have dyscalculia, a disability which makes mathematics significantly more challenging.
I have passed all of my relevant IGCSEs, including English and Biology. However, I got an E grade in math. I have not since retaken any exams / foundational skills, and I have 0 (and I mean 0) desire to take a foundation year.
Will this inhibit my admission into university, even if I am taking basic math at IB level and plan to take an English based course there? If I mention that I have dyscalculia on my UCAS, will they take that into consideration or reject me instantaneously?

You will need a diagnosis of dyscalculia in order to be able for it to be taken into consideration. I would contact the SEND department at your school to see what support they could offer. Most universities also require a maths qualification, so you will either have to do GCSE maths again, or take an equivalent IB course.