I think there are a couple of issues here. Empaths are often healers. We talk about healing in the sense of "directing energy" or "sending energy" but without even doing that, without being aware of it - we are healing those around us just by our energy. Added to this, empaths by nature tend to be chameleons, not only blending in but mirroring back. What occurs is the other person creates a projection of you. They don't necessarily see you but a projection of what they need at the time. This is why people will spend hours talking to you, they get lost in that reflection. And the projection is needed to bring the healer and the person into contact, to allow for the healing to take place.
When we talk about Reiki, there is that point where the healer knows that the body doesn't want anymore energy; the flow of energy comes to an end. The body can only take so much healing. So, how would a healer know when the healing is completed for a person on the emotional or mental level? If this is a paid client, the two of you discuss the issues and see if things are resolved. But what do you do when there is an unspoken healing, when people are in your sphere to be healed but not recognizing it - how do you know when it's over?
When people get into arguments or start to withdraw, there is always a "reason" but on an energy level; it's just time to end that healing. The healer may start to feel uncomfortable and assert themselves or say things that are not in keeping with the other person's projection of them. Once there is a crack in the projected image - it's over. The other person may feel betrayed or hurt; but what's really going on is that the healing is over. Or at least, with that particular healer. This is particularly true with co-dependents as they will latch on to someone else.
I should also point out that it's not just non-empaths who create projections; empaths are very good at it, too.
I wish I had a way to resolve your issue but I deal with this on a daily basis. I particularly dislike when I innocently say something and I hit a landmine. I know that for the other person, the anger is needed for whatever they are dealing with, but seriously, it hurts. But I have to see it from the position that this is helping that person. The co-dependents are particularly tricky to deal with.
My philosophy is that we are here to help one another but not to enable. We want everyone to step into their own power and see how great they really are. We all shatter and break and we all need help. I listen to others, I support them and I know how hard it is to get through the tough times. But then there's that point where you've heard the story too many times and you know they wouldn't move forward. I have a friend who is a powerful healer. However, she says that she can help anyone who is ready to heal but if they don't want to heal - there is nothing she can do.
In my opinion, on one level you are acting from the position of needing your own space - and that is perfectly reasonable. But on another level, as a healer, you are cutting ties because while you gave healing, the other person wanted to stay stuck and now, you are letting them go with the hope that they will turn things around. Bless them and send them on their way with the hope that they will figure it out. As a healer, you've done your part and you can let go. And while I know it's hard, you really shouldn't feel guilty about this.