Will I get fired before I hand my notice in?

I'm looking for some outside perspective because I don't know if I'm thinking clearly anymore.

I've worked for the same company for nearly 13 years and have been in IT management for around 6 years.

In February I hit a wall. I was exhausted, burnt out and ended up snapping at a member of my team. I'm not proud of it. We later talked it through, he understood the state I was in, and we're on good terms now. I took 3 weeks off work and then returned on reduced hours, doing some 4-day weeks.

Things seemed to be improving until the end of April when I got into an argument with a salesperson. My director initially seemed to blame me, which led to a heated discussion between us. We had a meeting afterwards where I explained my concerns and he acknowledged them. We agreed to draw a line under it and move on.

Since then, though, I've felt like things haven't been the same. My boss has seemed more distant and interactions have felt awkward.

Then last week I made the first serious mistake of my career. I ran a script and accidentally deleted customer data. I've been staying late every night trying to help recover it. Most of it should come back, but I think one customer may permanently lose some data because of my error.

I fully accept responsibility. I messaged my boss on Friday to say that once we're out of disaster recovery mode I intend to apologise properly for what happened. He read the message but didn't respond.

What is making me anxious is that since the incident, the MD and some of the other managers have felt cold and distant. Nobody has actually spoken to me about the mistake beyond the recovery work. No reassurance, no feedback, nothing.

The thing is, I was already planning to leave because of burnout. My original plan was to hand my notice in and leave mid-August. But all this has exhausted me and bringing that forward and leaving around 1st August instead. I need to take some time out before getting another job. But I have a plan to do something other than IT.

Part of me thinks I'm reading too much into people's behaviour because I'm stressed and ashamed about the mistake.

The other part of me thinks the writing is on the wall and they're losing confidence in me.

If you were in my position:

Would you hand your notice in sooner? I've got 9 working days left til I plan to hand in my notice

Would you wait and see what happens?

Does this sound like people processing a major incident, or does it sound like a company preparing to move someone on?

I genuinely can't tell if I'm thinking rationally at this point.

TL;DR: I've worked at the same company for 13 years and have been struggling with burnout for months. Earlier this year I took stress leave after hitting breaking point, then had a couple of workplace conflicts that seemed to change my relationship with my boss. Last week I made the first major mistake of my career and accidentally deleted customer data. Since then senior management have felt distant and nobody has spoken to me about what happened beyond recovery efforts. I was already planning to resign due to burnout, but now I'm wondering whether to hand my notice in sooner, wait it out, or whether I'm misreading the situation because of stress and guilt.