Am I crazy?

Ladies, I need to know from unbiased people if I'm overreacting and I'll try to make this short. In short, I live 30 miles from my parents. They are retired. I always go see them when I can but I work about 50-60 hours a week. They never visit me. They are never available to help me like when I had surgery or when we moved. My sister occupies a lot of their time. She has a one year old and my mom watches him. She drives by my house weekly to take care of him and stay with her and never visits me. I'm extremely hurt by this. My sister is now on her second pregnancy and is having a terrible pregnancy again. Going on bed rest etc. let me also say my parents are going out of the country on vacay (they refused to cancel it even though it's their 4th trip this year) when our baby is due and it's our first one. Now that my sister is in bed rest I will have no one to help me. My husband has limited leave and we have no family here.  I feel resentful of my sister because she demands so much of their time and because of her difficult pregnancies, it overshadows my happy moments. Her first pregnancy was during my engagement and wedding so she missed out on a lot. 
I confronted my mom
Tonight and told her calmly but sadly how upset I was.  She got very defensive and argumentative so I lost it. Started crying hysterically and telling her I felt left out. I never was mean to her or disrespectful. 
She hung up on me and then text me saying "forget Minnesota. You can't talk to me that way". We are supposed to travel out of state for my shower tomorrow. Then my dad text me and said " you were disrespectful and your mom will not be going to Minnesota with you ".  I didn't respond bc I'm so hurt and saddened that they wouldn't even listen to my message of being hurt. Let me also just say that my shower in California is in two weeks and nothing is planned. My sister totally dropped the ball and is now trying to figure all these last minute details and now she's having all these complications with her pregnancy. 
Obviously there's way more history to this story of things they've done to hurt me but do I sound insane? I plan on not extending the olive branch because I need them to understand me.