Dreading tomorrow night!!

My husbands mother and I have never seen eye to eye. We have had so many ups and downs. More downs than anything. My husband and I are going to go over to her house tomorrow night so her and I can talk about things. There is already a wedge between her and her son and I have a feeling this talk will make things worse. I'm not even sure on what all I'm gonna say. There is so much I could say but this woman is hard to talk to!! Oh lord help me please! Give me any advise you may have