Thinking about them while in a new relationship

After being discarded I did what was widely considered the right thing to do. I blocked them on all platforms and took around a year and a half to start dating again after going to therapy. I absolutely adore my current girlfriend she’s extremely sweet and always does things to make sure I’m comfortable and taken care of but I still often think of my ex wbpd. It’s often when I do new things with my partner I consider what it was like if I did them with my ex instead. It also doesn’t help that my ex was exactly my type and I haven’t felt as attracted to anyone physically since then. I just feel really shitty and don’t know what to do because I’ve done what was commonly considered to be the way to get over something like this and I still feel affected by it. I’ve been thinking of breaking up with them over it as I feel like I’ve been distant lately and it’s not fair to them. Just wanted to hear others thoughts on it I think the physical attraction is really what’s bothering me even to the point of wanting to text my ex again.