Upper-tier ill health retirement experience?

Hi all,

I'm a civil servant (alpha pension scheme) and I've been dealing with schizophrenia and anxiety daily for several years. I've tried to push through and keep working — I take some sick leave each year, but not much, mostly because I'm afraid of losing my job. The problem is that pushing through often means I end up doing no work at all rather than actually managing my symptoms, which I know isn't sustainable.

I already have flexible working and home-based working in place, but things have kept getting worse despite those adjustments. My job itself is genuinely low-stress and easy — it's purely that I can't function through the symptoms, not the workload.

I'm now looking seriously at upper-tier ill-health retirement rather than lower-tier, and I've got a few specific things I'm hoping people with direct experience can help with:

1. My psychiatrists describe me as "high functioning," which doesn't reflect how much I'm struggling day to day. Has anyone successfully been awarded upper tier despite reports using language like this, and how did you address it in the application (or on appeal)?
2. What kind of evidence actually carries weight for upper tier specifically — is it about permanence, about inability to do any regular work (not just your current role), or something else? What made the difference for you?
3. Has anyone dealt with the ill-health pension itself feeling too low to live on? Did you combine it with anything else (other benefits, part-time work you could still manage, etc.) to make it workable?

I haven't formally applied yet. I'm currently at the stage of gathering evidence and waiting on OH.

Any advice from people who've actually been through this process would mean a lot — I'm feeling pretty lost right now.