I am struggling to move on from my ex.

We broke up 1 year ago she’s dating some other dude now he seems nice I haven’t seen her in nearly 9 months and I have a girlfriend now who is the sweetest and I do like her but I keep coming back to this one girl this one relationship I’ve tried to move on I’ve changed physically I’ve made new friends moved away but I can’t not think of her and I feel guilty because I’m dating this amazing girl and I can’t seem to move on I’ve blocked her on everything I don’t talk to her or have any photos I only have memories that seem to show up out of my control and I’m being forced to move back for 2 months where I will definitely see her and I just want to know how I can move on I want her out of my head I don’t want to date her but I miss our friendship she’s the only person I’ve been open with and I fear that’s holding weight in my heart