My girlfriend and I are both shy about initiating physical touch

Both of us are women and I have more relationship experience and she has more physical experience, but overall, we are both new to everything. My last relationship didn’t end well and it left more damage than I realized in how I trust partners, but my girlfriend hasn’t given me a reason not to trust her so far. She respected that I was too scared to kiss on our first date, and has respected my physical boundaries so far and that makes me happy. I want to kiss her but I have no idea how to kiss but I think she’s waiting for me to initiate our first kiss. She’s expressed she doesn’t want to make me uncomfortable by asking again but I’m also worried I accidentally made her feel scared of me saying ‘no’ again and feel rejected. Every time I think about the first kiss, I feel an extreme tightness in my chest and start getting really anxious. I know she doesn’t prefer to initiate and isn’t used to it, but I don’t feel comfortable with it when I don’t know what I’m supposed to do. I feel like she understands it more than me and I would feel more comfortable if she initiated the first kiss, but I also don’t want to put her in a situation where she feels uncomfortable initiating. I’m planning on talking with her soon about it but what should I say if she isn’t comfortable initiating the first kiss, and how do we move forward with it if we’re both too shy about it?