Lost in My Desires After a Breakup

I just got out of a long-term relationship and I've been feeling really lost. Lately, every time I try to sleep or relax, my mind wanders back to memories with my ex and it turns me on like crazy. Tonight, after hours of tossing and turning, I finally gave in and tried something new that felt incredibly wrong but oh so right. I started by touching myself and imagining him whispering dirty things into my ear as he pinned me down in bed, his body heavy against mine while our lips crushed together in a desperate kiss. My fingers worked fast over my clit and I gasped at the intense pressure building up inside of me. I couldn't stop thinking about what it would be like to have him right there again. Then, out of nowhere, I imagined he had left and that I was alone, but instead of stopping, I pushed myself further and started pretending someone else was touching me. A stranger, maybe even someone I didn't know at all. The idea sent a thrill down my spine and made the rest of my body tingle with arousal. I moaned his name out loud as I rubbed harder over my clit, imagining him saying he wanted me to come for him but not letting me have an orgasm until it was his decision, this imaginary version of him seemed crueler than usual. My thighs were slick and warm from all the pressure, and then I reached down between my legs, pretending someone else’s fingers were pushing in deep inside. I kept going with the fantasy, feeling myself getting close but holding back because he wanted to wait for something more important. I bit my lip hard until it bled and whispered his name as if calling out to him from another room. Finally, when the imaginary man gave me permission, I let myself come with a long scream into the silent night, every muscle clenching and tensing up around that phantom intrusion. I lay there afterward feeling weirdly empty despite my orgasm, like something between dirty and guilty was left behind. Maybe it's normal to have these thoughts after a breakup but am I being too far gone? I've never done anything like this before, and now I'm just confused by how much I liked it even if it wasn't real. Anyone else ever fantasize about sex with someone who doesn't exist while trying to move on from an ex?