Katniss takes care of herself and her younfer sister
Katniss and her sister, including everyone else was at the reaping
Katniss and everyone else at the Capitol while Prim goes home
It all started when Katness woke up one day and everything goes down hill for her, she had dreams about her dead father and how he's alone now with her younger sister, Prim, to take care of. From that day, when she woke up is probably one of her worst days.
During the reaping is the most nerve wrecking moment for Katniss and Prim because one of them could get picked and leave the other even tho they only have each other. They ended up picking Prim and Katniss was not happy about it so she rushed to volunteer to go for Prim because it's better for Prim to be safe and not be in the Hunger Games
Katniss already had a tough life already and now knowing that she has to fight for her life, which makes everything worst for her. In the Capitol, Peeta helped her out with food and now that's putting a lot of pressure because he was bringing nice and a great friend to her, she can'T kill him in the Hunger Games. Adding onto that, Katniss and Peeta has feelings for each other just making it harder for them in the Hunger Games.