How to stay friends?

So I broke up with my girlfriend today, it just wasn't working for me, I wasn't happy, I wasn't looking forward to seeing her, I found us arguing over small things and me getting angry at all the little things she did. I just didn't feel the same anymore. but I did it in the middle of a date and I feel so guilty, she was so so upset and still loves me. I just feel so bad but I've made my decision, I do still care about her so much and want to be friends but I'm thinking maybe it'd be more responsible for me to give her space to heal. In two days from now we've agreed to meet because she told me she didn't say everything she wanted to in today's state and I agreed as i made it clear she had to respect my decision but I'm worried. I'm scared I'll agree to get back together or something out of guilt. I'm also nervous because i truly want to stay friends with her.