Red, I think your position is completely understable. If I see a change in the person towards me, I also wonder if it's worthy to leave the person.
For me, this is not a true friendship.
A friendship is for all life and without conditions.
Perhaps, I am learning to choose better my friends now. This is life.

I've got two problems: my seven years of isolation ravaged me not only in social skills but also in knowing people in advance. I really know them when it's too much late.
The second problem is that I'm so optimist. I see only the good side of life. So, I tend to put people in a pedestal. Neither my paranoical father affected me in that sense. He always said to me " you always see everything too much beautiful".