Acceptance is the only thing that can help you become unstuck and thus move forward.

Once you accept that its over and also how it came to be over, only then will your obsession with remaining in contact dissipate, and then completely disappear.

I'm not saying you're in denial about the break up, but true acceptance leads to letting go, and you've never reached that point of accepting how it ended.

You're looking for this understanding and meaningful ending, and sometimes we just don't get it. Sometimes we have to move on without the closure we seek and feel we need.
Sometimes we have to create our own closure for our peace of mind.

I suggest you work on this with your therapist, and strongly suggest you start by working on wanting to accept....