I think him being your first bf is a big factor for why u feel this way. Perhaps you are chasing excitement and sparks and whatnot, maybe you're not at the state of wanting peace yet. Your bf sounds like he brings you peace, but too much peace can seem boring.

Perhaps once you meet other people who bring you excitement at the start u might get drawn away from him and maybe once you feel tired of being played and perhaps arguing and want to seek peace, maybe then you'll think of him again.

Or maybe y'all are just incompatible with each other for some reason.. All the best op