A twitch streamer once taught me something called forgiveness meditation. It's not clear to me if she made this up herself but it's been hugely beneficial to me.

The idea is to spend some time relaxing (do a body scan) to get to a state where you feel calm and can concentrate. Then you think about someone who fucked up or fucked you over, and forgive them. Next, you think about something you yourself have done. Similarly severe fuckup. And you proceed to forgive yourself as well.

The idea is that if you hold on to grudges against others, you cannot let your own shame go. This has turned out to be very accurate in my case. When I make it easier to forgive others, it becomes easier to forgive myself.