Hey,
Sorry to see you're so down. Although you sound confused, within that message, I can see that you already have some of the answers to your problem.
I don't understand why your ex keeps changing his mind as to whether he loves you or not. Like you said, you should cut off from him. I know he was your best friend, but it doesn't seem like he is acting like one (whether that is intentionally, or unintentionally, I do not know).
Nevertheless, it does sound like you prefer life in Canada. I would suggest looking into which country offers you better job opportunities. Definitely move out from your mum and sister if you feeling "trapped". Pick a lively city. Go out, enjoy your life. If you have any uni or school friends, hang out with them. I have to say, I have felt like an outsider all my life, so I know how it feels like to have emotionally nobody close to.
If it was me, I would choose Canada over UK. better economy, and the guys on the other side of the Atlantic do seem more outgoing and forward. Maybe you and your ex can go back to being friends after this messy breakup.
Keep smiling, and try to find a new focus, or change of scenery- some distraction basically...
Some day all this pain will make sense- that's what I keep telling myself anyway