Sorry to hear that, that’s a tough situation. Anyone would struggle to focus with something like that happening at home.
About 5 years ago my father had a very serious accident. As the oldest son, I had to hold it together in front of my siblings, my mother, my wife, in-laws, everyone. Sometimes the whole family stays standing because one person is being the “strong one”, even when inside you’re not okay at all. It’s not easy, but it matters.
One thing that genuinely helped me was breathing. Sounds stupidly simple, but it works. I learned some breathing exercises back then and started using them whenever my head was racing. It doesn’t fix everything instantly, but it slowly brings your nervous system down and gives you some control again.
Another important thing is not letting your mom worry even more because of you. Let her know you’re there for her, that you’ve got her back. That emotional stability helps both sides more than people realize.
For the exam, one practical trick that helped me during that period was studying out loud. Reading and explaining the material with your own voice keeps your brain focused and reduces overthinking.
You’re dealing with real life stress, not just “exam stress”. Be patient with yourself. Take it one day at a time and do what you can. That’s all anyone can really do in situations like this.
Stay strong.