Difficultly with letting go of regret because my past actions have created my reality!

I watched a Rachel Hart coaching call which hit me hard. She said, “We can’t hate the version of ourselves from our past and expect to be in full compassion, acceptance and kindness towards our current version. You can’t create unconditional love for yourself if you’re hanging on to this bit of judgement, resentment, regret or hate what you did or didn’t do in the past.” (yes I take notes)
Here’s my dilemma. I am having such a difficult time letting go of the reality that I never had children and made a lot of choices in my life which have resulted in my crest reality! I know what Brooke would say, “How do we know I wasn’t meant to have children or be married or have a house etc…?” Because I don’t have them!” I’m arguing with reality and I’m having such a difficult time(all T’s I know) with this reality because I long for them and although I could still get married and have a house, I will never have children because I’m too old and tired. When I see parents with kids, I have so much regret and I’m so tired of it. I’ve been hanging on to this thought which feels heavy for far too long. Any suggestions for bridge thoughts to help me begin to let it go and move on? Thank you