@underneaththeash
Where do you live OP? My very intelligent (high earning) husband also finds online forms difficult to navigate. If you live in the SE I would happily come and help you - with my apple pen.
You can print off a bank statement or call your bank and ask them to send you one.
Each time you navigate a hurdle makes you stronger.
He's lucky to have you beside him giving him this perspective.
I find them very hard too, but I have to counsel myself out of the anxiety and panic!
I have put everything in to these forms a few times for internal promotion where there are five sections, one for each competency and you have to demonstrate a competency in each section but also, stay within a word limit. You also have to fill in your job and education history. I have had to ''dialogue'' myself up out of a slump when I didn't get through to the next round in the internal competition because my form filling wasn't up to their standards. It was difficult, but as @underneaththeash says, I had to accept that this is something I need to do better. I can do it better. I will learn how to do it better, there's a better job at stake.
Giving it lots of time helps. If you say to yourself, right, I'm going to spend 5 days on these forms, then if you get them done in four you feel ok, and not panicky.
However, when it comes to temp agencies, I would leave some fields blank. A temp agency once asked me for my pps number and like a fool I provided it. I wish I hadn't. This was before GDPR obviously but I felt drained after giving them every detail of my life and then they never found me any assignments.