In love with my ex

It’s been nearly 8 months since me and my S/O ended things and ever since I’ve been struggling to get over him I’ve had one or two dates that just haven’t gone well, all I do is think about him I’ve told him I love him but he’s so stubborn and just doesn’t respond to any of my messages, why can’t I get over him after all this time? I’ve never felt like this before I just want him back but obviously he doesn’t feel the same 😭 please give me some advice girls I’m sick of dreaming about him thinking about him and wanting him 24/7