How do I get over the past?

This is a very silly question but I struggle to stop thinking about minor things, and I want to know how I can just move past it. In my head, I try to be rational and I remind myself that whatever’s happened has happened and there’s nothing else I can do about it however I just feel like it’s constantly lingering regardless.

Sometimes I feel that to society, I have this picture perfect image I’ve built for myself, so when people gossip about a wrong decision I’ve made, I just can’t seem to let it go. I’m always thinking about it.

For example, let’s say I have a conversation with someone and I say something that might seem weird, immediately after that interaction, it just doesn’t leave my head. I get this weird, strange mixed feeling about it. After 2-3 days, that’s when it goes.

Another example is I made a huge mistake in my 20’s and I lied to my parents about it. Recently I’ve heard that my ‘partner in crime’ (a girl I stopped speaking to but was ultimately involved) has told her family and they’ve been gossiping about it despite us promising each other to not say a word. I guess I feel ashamed. Not that I’ve done it, but I’ve ruined this image of myself in other people’s head. I care too much about what others think of me.

How can I make myself better? Or how can I make myself realise that it’s okay, and there’s nothing more I can do about past experiences? I really just want to be able to let go but I’m unsure how:

I’ve been speaking to my therapist about similar issues and since it’s early days, we haven’t made much progress as expected.

Thank you so much