I don’t know if this is my BPD or a normal feeling? Yesterday was my(f27) sons 6th birthday, due to the fact of the pandemic and the state of everything we obviously didn’t throw a party like we do every year. Instead we had a dinner and cake for him at our place. My parents and mother in law were in attendance so it was a small gathering 6 people to be exact. My sister (f34) was supposed to be there with her husband and her daughter but decided a week before that they weren’t coming. My sister has health anxiety and has been dealing with the pandemic in waves. She has been coming over my house since 4th of July every two weeks or so after not seeing her for months in the beginning due to her being worried about coming out/being around people. Now after all this time with us hanging out she decided she wasn’t coming to my sons birthday cake. She gave excuse after excuse, first it was because my parents were coming, then it was because she wasn’t feeling good, then the final one was because it is fall and the flu season has begun. I told her outright (because I am learning to set boundaries) that I was upset and in retrospect kinda knew she was going to bail but wanted to have faith. She started to get testy and all defensive and trying to tell me that if the role was reversed she wouldn’t be offended or upset which is total bullshit. I told her that I was feeling a bit used because she only needs me when it’s in her favor. For example, she needed me at the beginning of quarantine for something super important, I came through. She needed me a few weeks ago when there was a black out and she had no electricity, once again I came through. I am constantly feeling I am always the one giving to others and receiving nothing in return. At the end of our heated conversation I said this isn’t anything to cause us to not be on speaking terms, you are allowed to feel the way you feel as am I. I was actually being genuine, I am in no state to be at odds with anyone. Now, for the past week she hasn’t been texting me or calling me, only called to wish my son a happy birthday. This happening has caused me to spiral a bit, I’ve been in a low mood, crying, feeling like no one cares etc. am I over reacting or is this normal? I need advice on how to proceed in this situation. 

Much appreciated!