Need serious advice - Work probation extended

Have you had a formal meeting with bosses, made note of where they want to see improvement and considered at how you can do that?

Yes, they said to pay attention to detail, to double check things before submitting for manager review, and to be consistent. I have done these things, but not to the full extent. I made 1 small error, which I think they will bring up.
I’m working during weekends and doing work for other colleagues, just to compensate, to show them i’m dedicated.
I don’t know what to do, and I’m afraid they will fail my probation.
I have a line manager, but she is not managing me. So can I say that there has been a lack of communication from their side, and the line manager is reporting to me, and the manager that manages me, is just reporting to that manager about me. I feel that there is a lack of communication there. I also feel at an unfair disadvantage because the other trainees have managers who manage them, and they have 1-1s with, so it feels more indirect in my case because i’m being reported about by another manager to my line manager who I have 1-1s with.
I also had mental health issues before the extended probationary meeting which I did not bring up. Family member had heart attack, and mother has health problems.
I’m worried now how to present myself and how to come across to show that I have met my objectives and that what happened in the past was a blip.
I feel heavily scrutinised over the past 2 weeks (post extended probationary period) as I have 4 additional weeks to prove myself to them.
I don’t know what to do ☹️ I can’t fail probation, it will look bad on all my achievements and future job prospects.

"They said to pay attention to detail, to double check things before submitting for manager review and to be consistent". That's what you have to do, you the full extent for the next 4 weeks. Stop making excuses and just get down to it. They have been clear, you surely understand the task, just do it and there should be no issue.
Book your own 121 meetings with whoever you need them with.
Leave home issues at home - that's how work works.
You don't need to present yourself differently.
You don't have to work weekends.
"They said to pay attention to detail, to double check things before submitting for manager review and to be consistent".

I shall. Thank you.

What if others are making mistakes too, and not getting any punishments like I did? Can that be noted down as unfair dismissal if they decide to fail my probation? I have the evidence too to prove it.

I shall. Thank you.
What if others are making mistakes too, and not getting any punishments like I did? Can that be noted down as unfair dismissal if they decide to fail my probation? I have the evidence too to prove it.