Relationships with Family

As I am doing this work I have found that I have a great deal of problems with family relationships. I feel that I allow myself to be the scapegoat for family conflict with grown children, my sister and my mom.

I tend to not want to make a bid deal about conflicts or addressing the problems that arise from relationships.
Example – Our daughter is a mother now with two small children. She gets very angry with me about all kinds of situations. We are on our way home from visiting her and her family, she was not happy that we only stayed three nights because we did not spend enough time with her children. We feel a great deal of stress while at her home and this visit our older granddaughter was sick with a runny nose and cough. Our daughter walked around with our granddaughter asking her constantly about with she wanted to eat, this or that or anything else. She is the same way about if we are playing with her, we need to play this game, or read that book. Always something different than we are doing. I have been not as polite as I can be because I am at my wits end. I want to last our and say, “Left us alone!”
My husband says we just need to be polite. I don’t say much because she doesn not really like me and I don’t address it. We have a lot an triangle relationships in our family and I feel very left our.
On this trip, our granddaughter fell out of the stroller I was pushing in the grass. I knew I should have belted her in but I did not do it. My husband screamed at me for doing this on purpose and allowing her to get hurt. I was so angry and embarrased about it. I take the blame for it myself and believe that I am stupid. Of course I did not wwant this at happen but I don’t defend myself at the moment. I stewed it over until I was alone with my husband that evening and I told him that I needed to not lash out at me, he needs to be concerned about our granddaughter but know I would not do anything on purpose. I felt ashamed but did not need someone else lashing out at me when I already feel so bad.
What do I start to do to get relationships on better grounds, have better boundries with my daughter? I did the relationship work a few months ago but I think I am so far off on normal that I do not know where to start.

Thank you,