Feeling a bit rubbish

[Gettingbysomehow]

I've been working full time for 43 years in a professional role.
I've had all kinds of awful colleagues, the bully, the sociopath, the lazy ones who fob their work off on you. People I want nothing to do with in my personal life as I have my own friends and my own life.
People know nothing about me and I like to keep it that way.
I've never once lost my temper, I've worked hard, got on with everyone, pretended to enjoy nights out and am generally well liked.
I've got 6 years left to go before I retire and I want those 6 years to be as aggro free as possible because I think I've had to put up with quite enough.
New person starts, not my boss, is ranked as junior. I don't like her but do all her training and make her feel welcome. Listen to her problems.
As time goes on this person becomes more and more of a pain in the neck, complaining non stop, bossing everyone around, making life difficult for people.
One day she started on me thinking I'd be a soft touch and I absolutely lost my shit.
I have never before been so mean, so nasty and so personal but after all these years the dam just broke. I thought I do not need this shit this near retirement.
She isn't speaking to me which is difficult as we work together.
There have also been numerous complaints about her to management by other staff but they have done nothing.
But I feel so bad, I have controlled myself all these years being a decent, helpful person and I end up doing this. I'm not even menopausal I'm well post.
I just don't know how to handle the situation after this. I should have handled it better with my experience.
Any suggestions?

Apologise?!

you feel compelled then file an informal grievance with HR, which amounts to a discussion with her manager.

Forgive yourself.

How would you advise someone else to handle the situation professionally?

Were you that bad? Are you so surprised and disappointed with yourself that you are overreacting?

Own your own shit. And don’t apologise.

Why?!

I'm not going to apologise that's for sure. It's meaningless, I meant what I said. I've comforted her "victims" when they have been crying in the rest rooms and watch her make juniors lives a misery having them running all over the place.
I'm really just ashamed of myself for losing my head like this.
I've reported it to management and they can sort it out.
It's about time they did something about it.

The dam broke because you haven't been honest with others (and I mean this kindly). It's ok to point out faults to others in a constructive way. It's ok to suggest better ways of working. And it's ok to keep on at senior management to address issues you see. In the meantime, apologize to her- she sounds unpleasant but you dumped years of pent up grievance onto her. Moving forward, you need to be a bit more open and honest with others in your daily working life, for your own sanity.

No, I think this is completely wrong.

OP you have an entire career of being fair, balanced and nurturing new talent. This person behaved badly and needed to know about it.

Own it. Stick to the principles. Don’t apologise. You’ll outlast her by the sounds of it, even with only a few years to go until retirement. I can’t imagine her being around for long if people are complaining about her that much, that soon.

It happens. You can only bottle it up for so long. Just do your job. Talk to her as if there isn’t an issue. If others have an issue direct them to HR. If she is being awful just turn around and walk away, or keep typing. Just keep reporting her.

You should apologise for the way you spoke to her, if not the content. Being 'mean, nasty and personal' has no place at work, whatever she has done.

There’s a big difference between professionally telling someone you think their behaviour is unacceptable, and what it sounds like the OP did, which was unleash years of pent-up frustration onto someone who might be a bit of a sh*t but probably didn’t deserve a ‘mean, nasty, personal’ dressing down.

OP, I would apologise. And consider therapy. What you describe is actually quite toxic. You might not be the ideal colleague you think you are if you are carrying all this aggression and resentment into work with you.