Is this fiction or real, because I am laughing really hard here after reading this whole story. I mean your neighbour friend telling you
"We are inseparable" when you are trying to break out from the bond you created means it's going to be taking months before you break such bond, that's if it is going to be possible.

I wish I could give you some advice but the truth is after reading the whole story, I am as clueless as you are but maybe you can start by trying to love him maybe something beautiful can come out of both of you. You know, there is no harm in trying to love him in your little way.