Aww, Hope. It seems like you have an overwhelming want and need for a long-term human connection. it really seems like you just want a relationship with a caring other who isn't going to leave. At the heart of it all that is all any of us wants, really. It is a very human thing to want and need.
Do you know that with the appropriate therapy and help from a well-boundaried and ethical therapist it is possible to get to the point where you will be able to find and sustain a long-term connection with an other outside of the therapy relationship? The awful paradox is you are so fearful of the eventual leaving it prevents you from making a sustained connection with a therapist who will be able to help you get to that point. What to do?