Been a few months since my 7 year relationship breakup. Started having nightmares about it

It feels like it's taken forever to get to the point where I am now, even though its only been six months or so. I thought I was nearing the 100% ok mark and then a few days ago I started having these dreams about the end of our relationship where we didn't communicate much and she gets nervous and runs off when we try to do something together. I'm sure it has to do with fear of making the same mistake with someone in the future. I don't want to pretend I didn't mess up, but how do I make the burden of responsibility a little lighter?