Sexual past sin haunting me

I don’t really know what else to do so might as well post here.. when I was “young and turnt” I was unfortunately fornicating with multiple people over the years. I accepted Jesus into my heart after having an encounter with him almost 2 years ago, and I’ve changed entirely so much that I feel like I was a completely different person before Him (I don’t even check my old photos/videos since it gives me such an eerie feeling).

There is this person I’ve fornicated with 4 years ago and it was essentially the best sex I’ve had. Since I’ve came to Christ, that memory is haunting me for the last 2 years. I’m talking about opening my eyes and thinking about it immediately until I close my eyes. It is replaying in my head constantly, during work or conversations with people, I used to dream about us having sex multiple times, sometimes days in a row. I’ve felt trapped and no one around me knows the spiritual torment I’ve been through except for God. I’ve repented, extremely changed everything I knew to what is righteous, turned away from my old ways, sacrificed so many relationships and friendships for the sake of being closer to Christ and the torment has gotten so bad. I cannot take this or do this any longer. I’ve tried literally EVERYTHING.

The Holy Spirit has put it on my heart to fast for three days and so I was obedient and I did a 3 days water fast, without social media too so all my time I’ve spent with the Lord. I gave it my all and I was extremely nauseous and tired (had to go to work twice in these 3 days) but I didn’t give up and made it. Yesterday I’ve finished my fast, repented, renounced and divorced any demonic covenants I’ve entered and felt really good. After taking a bite I’ve thrown up excessively a minute after and in my head I thought “the spiritual oppression is done, I am finally free.” I prayed before bed as usual and asked God to protect me during my sleep. I went to sleep and had a bunch of weird but kind of normal dreams, until I’ve suddenly found myself in my bed (in the dream) thinking about the sex flashbacks once again and using a vibrator, and I woke up from me having an orgasm, it was THAT intense.

I don’t know anymore if I am even worthy of Christ. Maybe I’m too unholy for this. I’ve tried and changed everything, I even had a few special encounters with Him during my two years but He can’t seem to help me escape it. I don’t have anymore strength in me.

(For context, I don’t have any friends that are believers or a church since I am living in a non Christian country. Plus it is only flashbacks with this one individual, my past sexual partners I’ve moved on from and didn’t think about them once.)