Is it normal to love someone so much?

Love is dumb, they're right. In example, right now I'm just going through so much crap with my ex. It's annoying how much it consumes me. Its easy to say dont let it consume me but its not easy to do. Even when I finally "move on" and thinking about him makes me sad but not that sad, I feel like everything is not real unless I'm with him. I feel like I'm just living this pretend life like everything is fine but I know deep inside everything is not fine. Even when I look back and think about all the bad stuff he did to me such as look down on me, lie to me, neglect me, etc if I see his name pop up, or hear his name, hes all that matters when there's more important people I should put first. Yeah he didn't treat me like I should have been treated which he admits, but I still want him. If it wasn't for how he treated me and how I deserve to be treated, I would still be with him no matter what. He's everything. Its kind of like that saying "sometimes the reason why you can't let go of what makes you sad is cause its the only thing that made you happy." Rationally, I would never give him a chance unless he finally gets his act together. But wholeheartedly, I would always give him a chance. What doesn't help is that he keeps communicating with me when he's the one who wanted to split up. I told him to stop and he said okay then started doing it again. I want to tell him to stop again but is that really what I want? Not really.