Advice Please??

Hi guys need some advice

I have a brain tomour which was discovered at a young ago along side other health problems.i used to get high rate care and high rate mobility. When it switched over to pip I had to go to a tribunrul which I got high rate daily living and standard mobility .meaning I lost my mobility car.

I suffer bad from my probs with my brain tomour can't walk hardly any distance. Av also got PTSD as I was driving my car in late 2014 and a bus hit me. Car was a write off. I can't travel anywhere without a friend it stresses me badly and have panic attacks. I'm due to get the HOW YOUR DISABILITY AFECTS YOU FORM. I'm thinking bout putting a change of circumstances because my condition is getting worse.

I'M gonna try and get letters off different profesionals who I see. To back me up

AM I DOING THE RIGHT THING??