hi folks, can I get support and perspectives on some shame/guilt I'm experiencing?

Context, I have a long term partner. We were long distance (online) and nonmonogamous from the start, but since I have moved to his country we have been functionally monogamous. It's taken some time for me to feel at all ready to connect with other people due to some mental health issues that are on the major upswing the last few months.

Recently, a friendship that began back in December has become physically affectionate and I started to experience a bit of shame. I felt like I was doing something wrong. I told my partner this, and he was wonderful about it as he is about these things. He told me that he wants me to be happy doing things I want to do. I told my new friend about these feelings, and they were wonderful about it too.

I needed to have the conversation around safer sex with my partner, i.e. what does he need from me to feel empowered with his own sexual health (e.g. does he need details? is trust enough that I am going to be responsible with regular testing and practises that are lower risk?). The conversation was informative and connecting, I told him it felt a bit scary on my end to have that conversation (I think it triggers some big guilt in me from years back when I dragged a previous mono partner through the "let's open our relationship" gauntlet).

But I still can't shake this guilt. I trust my partner's words, that it is okay, that he is comfortable, that he trusts me.

How do I combat the guilt?