I don’t know how or what to feel right now. My gf(25F) has left me(22M) to hang on the day of my brother’s funeral. What do I do?

I'm out of town for the weekend for my brother's funeral which is today. It starts at 12 yet here I am on reddit needing to vent because I don't know where else to go and I want to at least try to clear my head before it starts in 3 hours. My gf and I got into a disagreement last night because I found out she lied to me, or rather intentionally kept some info from me which i'd say is pretty important to talk to your partner about. Long run down; I found out she was talking to her ex-gf last year (she had a bi phase). Apparently her ex had called and they were on the phone discussing what lead to them breaking up. I also found out her other friend used her as a courier to drop off some of her clothes, which was upsetting to me because as far as I'm concerned she always said it was a specific taxi who was used as a courier whenever she needed stuff dropped off. I got really upset last night. It got worse when she started self victimizing instead of even apologizing. At this point I got more upset. Typical tendency of her she faults me for being harsh. Like she always does when she's wrong; she finds that smallest thing to say I did wrong. We went to bed and while going to bed I thought about how I was going to tell her I forgive her for what happened in the morning. I woke up to a voice message from her. Telling me that I should be strong today. What ticked me off was when she said she would be going offline for a while, a while being the entire day and evening so if I dont hear from her she's going to be busy working on something. Extremely random and extremely out of character for her. I felt betrayed and hurt that she would be so selfish as to take time for herself when she knows what kind of day today is for me. I sent a vn letting her know how her decision has affected me. She responds some hours later saying she was going to go shopping and wash. Wash what? We did all the laundry together on Thursday. There was nothing left to be washed and it surely wouldn't warrant her needing to be gone for such a prolonged time. The proceeding messages came with her asking what she did wrong for me to be so upset and she even hung up on me. Idk how to think rn. I got a lot on my plate with the death and the other side of the family being toxic or everything. I don't even have my partner to be there for me.