Be strong, they are going through so many emotions right now and to be frank they are telling them that having us there will put them in risk for relapse. They need to learn to be independent before they can share themselves with anyone.
Doesn't mean they never loved us, just means they loved us when they didn't even love themselves. Nothing that happens will take away from any of the love you shared but the best thing to do is to walk away and hold those good memories.
Something that helped me was to do a fake funeral for the man I was with and write his eulogy because truly coming out of this he will be a different person.
Best of luck and like I said if you need any advice at any time message me and I will reply :-)