Wants to leave again after a month!!!

[MrBond]

"And if I wasn't sp persistent the first time he left we may have fallen back in love with me."

Don't believe this. He has shown no signs of respecting you and actually continues to blame YOU. He has taken no responsibility for his own actions. Tell him that when the D happens you will not be friends.

Personally, I would not go on the trip. I would tell him that he could go and when he's gone you are going to pack up his stuff ready for him to leave because you feel like he's been like a heavy weight dragging you down. And that now that he's leaving you can be free. He's not going to like that but you have to cut him off.