Is it normal for wanting 2 write hate letter 2 my sister

Both me and my sister were adopted. We have very big family. Total 18. She was adopted at 2 months old. I was adopted at age 12. She is 2 yrs. older than me. My sister and I use to be very close. I use to worship her, navy her for sweet, kind, smart, honest. I felt very closer to her than anyone else in the family. I trusted her very much about anything we did or talked about. About few yrs. ago, 2 months before my dad died, we talked about, how we were brought up in the family. I thought we were bonding as sisters. Durring, my growing up years, she wasn't around much. She always had things to do or places to go. I'm physically diable and couldn't go any where. So when I told her, how I was treated and not in good way. She didn't want to believe or agree with me. After that talk, everything went down hell. Week of my dad died, I couldn't go to his funeral, because I just had a knee replacement surgery 72 hrs. ago. No one in my family called me aobut my dad passed way, after 3 1/2 days later on my voice mail. When I called my mom to give my symothay, all of suden she started to yell at me and hanged up. Then, I find out that my sister told everyone, that how I was telling the way I was treated. She totaly betray our trust and our bonds. From there on, no will want to do anything with me. My relationship with mom has gone very bad, that we don't talk anymore. My whole family and mom has not visited me for 10 yrs. I can't drive anymore, due to my disabilty. When I use to drive, I would drive 5-6 hrs. every holidays, any occasions, even though, it was hard for me to get around with wheelchair. Anyway, my sister has brained washed everyone, by bad mouthing me to them. Recently, I just found out, that they all had family reuion and I was not invited or included in the family pictures. I found out on Facebook, when I was checking for my messages. Now, I hate her more than ever. I really want to tell her off. What should I do? Is it normal me to feel so much hateful towards her?