My family betrayed me

Went to a family bar mitzvah. The first grandchild of my closest sister, which I refer to as sister 2. Was told by my nephew who is giving the event no cousins are invited when the invites went out since my kids didn’t receive an invite. Then I found out I’m going to the event that my older other sister kids and grandchildren were all invited. I’ll refer to her sister number one. I was invited with a guest so I thought I’d bring my son who is single and alone before I did so I asked my nephew if cousins were invited at which point he told me they were not to keep the numbers down.
Then I talked to my sister number one and said to her actually sister number two and said to her I don’t know whether to bring my sister or not because I don’t wanna hurt any of the other cousins feelings since I understand none of them are invited. The only thing she told me was that sister number ones son wife and two kids were invited and then she went to this long explanation of why they were invited. The only thing she told me was that the wife and son and two kids were invited, however she never mentioned the other sister, other son and wife being invited who are stepchildren.
So I ended up bringing my son as my guest and my daughter and son-in-law were excluded. However, when I went to the event sister number ones children and grandchildren were all there. Conveniently, my nephew never told me about this and lied and also conveniently my sister number two never told me about this since she only mentioned a few of them. I was shocked. I’m very upset and I saw sister number two when I walked in and I said wow congrats but it seems like certain cousins made the cut. She walked away and started asking my son. What’s wrong with your mother? He said he was staying out of it.
Now I should’ve said that, but I was so shocked that was lied to by both my nephew and my sister. During the event, I tried to make up with my sister and she said I really love you but she still really seem mad until the very end even when I say goodbye she’s kind of shun me. I was attending the party so I was gonna find out either way. Was I lied to and I feel so hurt. Being oversensitive?

By the way, my niece who is sister number two’s daughter told me she was upset that both of my kids and my son works left out, particularly since sister number ones children and grandchildren were included. It seems I was the only one concerned about the other family members feelings and no one else gave a crap. They couldn’t even be honest with me so I didn’t walk into the event feeling totally betrayed. It’s put me in a very awkward situation, but I don’t feel I should be apologizing to my sister. I never would’ve reacted like that have I’ve been told the truth.