Another abdominal wall hernia?

Hello! (I'm female, 17 years old.)

I had a small abdominal wall hernia in my upper abdomen two years ago which was operated on, but for the last few weeks I've had the feeling it's back. I'd suddenly lost almost 10 kg, vomited a lot and had pain/sensitivity in my upper abdomen. So I went to the surgeon a week ago and the ultrasound showed that the hernia had only reopened slightly (there was no hardening when I palpated it), but it still hurts a lot. Now I feel constantly swollen and have an inflamed lymph node under my armpit… On top of that, my stool is black. I feel bad and ashamed that it hurts so much because the hernia is very small, but somehow my upper abdomen feels weak and sensitive. If I eat just one apple, my stomach gets really big and hurts… Right now I feel sick again and it burns and presses… I don't know if I should go to the surgeon's office tomorrow morning, since I missed two days of school last week because of it.

What can I do? Am I overreacting? Thanks for the help!