Op I’m not an employment lawyer but I work in this arena and manage similar issues.
thr bottom line is what you are posting here is inconsistent.
you say you were trying to improve and a reasonable adjustment was a bigger monitor. But on knowing the issue Over two to three months you never found time to see an optician to resolve your eyesight issues. In addition using larger font didn’t help , which confirms a bigger monitor would not have changed the issue either; it was an irrelevant adjustment. You had the ability to make the font huge and it still didn’t help.
you also state you didn’t know there was an urgency, there Is always an immediate requirement to do your work to thr required standard. You clearly knew you weren’t performing to the required standard, as you state you were trying to improve, so why no optician visit and the bigger font didn’t resolve the accuracy issue is difficult to comprehend.
you also state you suffer from anxiety which is compounding the issue, so wished an adjustment there too, but seem unable to articulate what that is. Other than to indicate they should make their delivery gentler. Delivery is subjective and very hard to argue. What one person sees as harsh another can see as gentle.
right now you’ve failed to show what reasonable adjustments would have supported you to do your job to the required standard. As a bigger monitor and being nicer in their messaging clearly isn’t it.
in addition uou should have acted as soon as you were struggling, immediately asked for adjustments and stated what you were doing ie glasses, use of font, training on MacBook, revisiting your gp on your anxiety etc you seemed to not have done at least the optician claiming over several weeks you didn’t have time.
im sorry but if you’re going to stand a chance here you need to be able to prove you asked for the adjustments in a timely manner and they would have supported you to do the job, right now, it appears Neither is the case.
you asked earlier why it mattered if your story was muddled. Accuracy is important. Particularly if you wish to go to tribunal, as your company will be accurate and present a very different story. The story many of the posters here are picking up.
people are trying to help you. There is no point going down the tribunal route if you can find someone to support that, if it will just cause you stress and end up with nothing.