How to resolve regrets about ending a relationship and be sure I'm ready to move to new encounters?

I broke up with a partner of 5 years in fall 2020. Got with someone new few weeks later.
Ended that relationship last may but now I feel regret about ending the first relationship.
I'm not sure if I feel guilty, or if I'm mourning that relationship. I imagine what it might be like now if we'd stay together.
I'm now interesting in someone else but I'm worried I keep comparing them to my ex and I'm worried about getting too involved in case I'm not yet ready and don't know what I want.
For example, in general I don't really want kids but with my ex I felt like I was prepared to have a family and settle down. The new person I'm seeing doesn't want kids which would normally be fine but now I reflect on what it might have looked like if I'd stayed with my ex and then doubt my decision about kids
Asked by Ben

Hi Ben, Thank you for your question, it sounds like you have been affected by the ending of that first relationship ever since.  I feel the first place to start would be to explore that first relationship and how you are feeling now about it and also looking at in particular the regret.  If that 'regret' could talk, what would it be saying to you.  Are you able to articulate exactly what the regret is?  This is something that can be explored in therapy and in time worked out if it is not clear at the moment.  You also mention that you do not want children but this is also something you were prepared to change for the first partner.  What was it about that partner that meant you were prepaid to change your mind over them.  In therapy you could look at if you are mourning that first relationship.  Being able to explore how it is, not just in feelings or emotions but in thoughts too would also help you to work through that mourning or regret.  I wonder if now you are comparing all your new relationships to that one?

It sounds like you are now in a position where you are feeling confused about what was and also what it could have been and also what you might want in the future, possibly even about whether or not you want to have children. 

I think there are a number of things to explore:

The ending of the first relationship

How you feel about that relationship now

The reasons for comparing each new relationship with the first one

What it is you are really wanting/looking for now, so then you are able to form new meaningful relationships

I think once you have looked at these different elements, your thoughts will become clearer and you will know what you are wanting.  At the moment it may feel like a mass of 'I just do not know' and the emotions too are making it all the more confusing for you.

It certainly sounds like there is some unfinished business with that first relationship that needs to be worked through.

I hope my answer has given you some food for thought.