Hey, y'all - sorry in advance for the super long post. Here we go...

So, for context, I recently chose to spend some time away from my Girlfriend, because we had been fighting a lot, and I knew that there were quite a few things I needed to change. I came back feeling great - cleansed, renewed, and like a better Man thanks to therapy, introspection, and healing.

However, when I came back - my Girlfriend told me that she had made a new Friend. A guy. Which I thought to be weird, since we were talking on the phone every night while I was away, and she normally would tell me the same day when she met someone cool at work, etc. So that was kind of odd, but whatever. Then, this past weekend - the Friend invited her to a Museam, the catch - he only had one ticket... Only my GF could go.

So, trying to be the good Boyfriend, I wished her a good time; but did tell her how anxious it made me. She reassured me that she does not have feelings for this guy, and that she simply wants to make more friends (which I know to be true, she hasn't had many throughout our relationship). But then, oh my gosh, when she left - I felt SO much anxiety, panic, and abandonment. It didn't take long for me to realize that I had traumas associated with this - in my VERY FIRST relationship my Girlfriend told me she was hanging out with a guy friend... who I found out she was screwed. Furthermore, I had been on the OTHER side of this, too! I had female Friends who I always liked, but knew they had boyfriends... so I never made a move. Funny enough, they did.

Anyways, we got into a huge fight over this when she got back, as I first broke down to her, telling her how I truly felt while she was away... then my emotions got the best of me and I was "the jealous bf". After a day and a half of fighting, we both agreed that we want to make this work, and furthermore (by my understanding) that this is a problem I need to fix; I can't put my traumas on her. I made some suggestions such as her checking in with me periodically while she's out w him or other guy friends, for that matter... I trust her, truly, but the layers of hurt with this subject are really f'ing hard to break through. So my question to y'all is --

How can I possibly work on releasing those scars? How can I lean into my trust to outweigh the hurt of the past? How can I let go of these intrusive, negative thoughts which I know not to be true, and enjoy the fact that she's having fun and gaining new friends?

Thank you!