I 31F often joke to my friends that my best friend 31M is my favourite person both by choice and not by choice. I'm obsessed with this man. He's my best friend in the entire world but I'm also so painfully in love with him, but it's not reciprocated. 
We've had a very confusing and turbulent relationship over the years we've been friends and although my feelings for him never changed, everything was fine.. Until he moved in with me 6 months ago. 

We live in this weird "friends/relationship" scenario in my head. We have seperate rooms and we're purely platonic but we share a home no different to any of my past relationships so it's easy for me to fall into that bubble. 

Recently he expressed a need to meet new people online, mainly texting friends and stuff to break up his day, which I get and understand.. But he met a few girls and has been staying up all night texting/phone calling this girl. To the point he doesn't even try to make it not obvious. When we're gaming with friends, he always getting us killed or landing last so he's miles away from us, running into walls or the worst one for me, just ignoring me when I talk. He asked me a question about a game we were playing yesterday and I had to answer him 7 times before giving up because he wasn't listening to me and instead texting. 

I'm so used to us being each other's worlds, he is my 'favourite' person and for the longest time I was his.. But tonight, he's in his bed texting this girl whilst I sit alone and spirial in my thoughts and I don't know what to do. I need help. I need to break the tie I have with him whilst keeping our friendship because its killing me. Please help me.