I have someone at work who drives me bananas, sorry drove me bananas. Every time she would talk to you, she'd say "you're not listening". She is the only one who does this. Now I cannot be bothered. Like you said, she ain't worth the energy.?
Starst, if you feel guilty, that ain't terribly positive. Move the friend out of your life. Her/his time in your life is over. You need friends who LOVE you.
Yes I understand you. Friendship shouldn't mean guilt trips though. Try not to feel terrible. Sometimes, you'd spend more time explaining why that person upsets you and then he/she might deny it as well. Life is too short for all that.
Terrible person? No. You just have to know what you want and don't want. I had a friend in whom I confided and she then proudly told me that she had told her children, friends, colleagues, etc. all about a private problem. That for me was too much.
That's where the selection process comes in. If that is her value system (i.e. I ask you to trust me and then I betray your trust), is she worth it? Methinks not.
Everyone has their value in life and even if I don't understand their purpose, I can understand that. It doesn't mean that I will want them around me though. I try and distance myself from people who are trouble. I don't want to invite that into my family and risk exposing my kids to their problems.