Feeling "loved up" - especially in newer relationships changes your brain chemistry in a massive way, commonly described as a form of madness.
You have to be objective, step back, look at the situation from other perspectives - this is not your fault, evolution has wired us up this way. Take a few days off from everything - physical exersion is a great way to get a bit of balance back, find other distractions - films, games, DIY, art, music, anything really.
We've all been there, all you can do is try to take a bit of break or a gap from thinking about it. I'm sure many of us can look back at times like this in our lives and remember how much of a massive deal it felt like at the time - but it's nothing in the grand scheme of things and it passes. It's just not worth worrying about to this level.
Good luck matey, just rember it'll all pan out how's it meant to in the end
Thank you for your kind words. I've been through a break up before but this is like nothing else I've ever experienced. I didn't know anything could feel quite as strong as this. I'm literally mindless right now. I can't focus on work and have zero appetite.