I have to write a script for a four minute video about how disability affects peoples lives and I'm really struggling.
Not sure this will help, but something to consider....
The lives of whom?
1. The disabled.
2. Those without disabilities.
3. Both 1 and 2?
If you get to choose, I would focus on either the first or second, not the third option. Once you have some kind of target audience, you can proceed. If your target audience are those without disabilities, you can detail imagery of a handicapped person unable to do something by himself (almost stranded out in public somewhere or something emotion-evoking).
If you address the disabled, that is another situation. Maybe your target audience is those with disabilities with chips on their shoulders. Maybe create sarcastic scenarios where he sees how absurd he behaved to others based on examples provided.