Taxing car after PIP ends

Hi everyone.

My car has been exempt from tax for the past 3 years as i was awarded PIP (due to end stage double hip arthritis).

My situation now though is that my PIP award ends tomorrow (20th Dec). I've had my car tax V11Z reminder form come, and the car tax runs out on the 31st Dec. Although i sent back my PIP review form about 6 months ago, i haven't had a review. I did have a text a few weeks back just telling me which company will handle my review, but they must be very busy as i've not had the review (i don't actually expect to get awarded PIP again as, although i do have some physical issues, my original problem has been fixed as i had both hips replaced last year).

So basically my question is, as my PIP award ends tomorrow, and i haven't been told it's being renewed (and i don't expect it to) - how do i go about retaxing my car? I've just gone through the online method, but there doesn't seem to be a way to de-select the 'disabled driver' option. Do i need to get a different form from a post office? Or should i be calling the DVLA to tell them? When i was going through the motions online to renew the tax, it said if i click 'continue' then they will use some database to check my eligibility - i'm not sure if doing that would look like i was trying to get free tax when i'm not entitled though. Just a bit unsure what to do next really!

Thank you in advance!