[quite=fightin]As long as I don't give her reasons to be angry with me and don't act like an emotional basket case, she has only herself to blame and be mad at. [/quote] I don't think this is at all the right attitude to have. DB isn't about 'not making her angry'. You can't really control her feelings. Why would you tolerate disrespect just to appease her? In my opinion, if she's texting OW, just leave. If she's talking about OW, stop her and say you don't want to hear it. SHE IS NOT YOUR BEST FRIEND RIGHT NOW. She is trying to HURT you. She has ZERO RESPECT for you.
Stop asking why she's disrespecting you. If she's texting OW, Say that if she does it in front of you, then you will leave. PROTECT YOURSELF.
You can do this, fightin. The key is to frame your thoughts around what you can control. YOUR thoughts. YOUR actions. YOUR emotions. YOUR words. YOUR reactions.