OP, well done for putting your children first and finishing it with her.
As PPs have said, don't be surprised if she now tries to hoover you back in when she realises you aren't begging her for "another chance"
This link may help you spot the cycle of abuse (and you'll suddenly see your past with her in a very different light)
www.talkspace.com/blog/cycle-of-abuse-domestic-violence/
My advice at this stage would be:
Block her from your phone, email, social media - do NOT accept any form of contact from her. If you have her friends/family on social media, quietly remove them
If you have ever given her a key to your place, change your locks. You can buy new lock barrels in B&Q for under £50, there are loads of YouTube videos showing how to replace them yourself. I did mine a few years ago, all you need is a screwdriver for most doors.
Sit down with your kids and let them know that you're sorry you haven't spent as much time with them as you'd like lately and you want to be there more in the future. Maybe start planning something nice you can do with them once lockdown is over or outside activities are back on - this will give both you and them something to look forward to and start seeing the positive changes now that the abuser is not in your life.
Depending on your relationship with your kids' mum, maybe let her know what's happened - it's not unknown for abusers to try to target their former victim through ex partners, especially when there are children involved.
Tell your friends and family. There is no shame or embarrassment for you here - that shame belongs solely to her. They are not going to think you're weak for being in this relationship, they're going to think you're strong for leaving and putting your kids first.
If she does manage to contact you - especially if she comes to the house - stonewall her. "I do not want any contact with you whatsoever. We are over. If you continue to harass me I will contact the police." Then follow through. If she's at the door, don't open it. If she causes a scene outside, call the police. She has used her screaming and noise to control you through embarrassment in the past, don't let her continue to control you with it.
Consider getting counselling for yourself to work out how you got sucked into this relationship and what made you stay. Learn about boundaries and how to spot the danger signs.
Well done again, you have a much happier life ahead of you, and so do your kids [flower]