Fling from the past

So I have an amazing loving caring boyfriend. I love him so much. however.... there was a boy I used to have feelings for we had a thing with eachother we both had a crush on eachother he always used to call me when he was drunk early hours of the morning and he used to FaceTime Me for HOURS almost every night and tell me I was beautiful and that he loved me.. we used to talk every day but during the day he used to be more blunt with me and seem uninterested I got so confused by all the mixed signals he was giving me & we never got together because he lives far away but I’ve met him in person twice. We ended up sleeping together (way before I was with my boyfriend, like 2 years ago) and he didn’t say much to me after he went back home.. a few weeks went by and the conversations were less affectionate and more blunt, I finally said to him that I was hurt because I felt used like he just came to see me for sex and we had a small argument and he said its a shame I live so far from him and all that bullshit. I was so hurt because I genuinely had feelings for him. We apologised to one another and then didn’t speak. But occasionally he would reply to my stories and try to make conversation with me, it just felt like he was trying to show me he still cared. anyway over time I got over it but I still have a soft spot for him and that makes me feel so guilty!!! I know I don’t love him, I think I just love the idea of him if that makes sense because of what we could of been. and now that I’m in a relationship I decided to remove him on everything, delete from snapchat, unfollow on Instagram and remove him from following me. And I genuinely forgot about him and then about 2 weeks ago I wake up and what do I see, hes followed me on Instagram again.. (Bare in mind we used to go through stages of not talking and I’d be hurt so id delete him and then he’d add me back) it was like he would always want to have me on some sort of social media and he would always view every story & like everything I posted. anyway my mind went crazy it brought back loads of emotions and I felt bad & guilty and the worst bit is I didn’t want to remove him from following me... because I always wanted to keep contact with him, but I removed him anyway. I’m just so confused as to why after like 6/7 months has he now just noticed I’m gone and why has he tried to follow me again? And it was yet again around 2am so he had probably been thinking about me when he was drinking. Its just making me feel like I’m not a good girlfriend for still being affected by his presence and i dont know what to think of it, any opinions or advice are greatly appreciated.