Help me fight against my body

Hi everyone. I am Joven Adrian Caunan and will be taking my PSLE this year. All my life i have never known how it feels like to have soft and non itchy skin. I envy my friends who can do PE under the sun. I envy people who do not need to cover up their skin. My mummy says im so loved and so blessed to have people who loves me to care for me because then i am never alone. I know that but i am also aware that my parents cannot afford my medication because you see i have a younger brother who is autistic and need to attend special school. Because of my medical expenses, my parents wanted my brother to transfer to a mainstream school like me so they can save on school bus and school fees. Every time i hear my parents digging their coins from their piggy bank, i know that they have no money. I feel sad. My skin is so flaky, swollen, and filled with wounds. It is so itchy that i cry. Mummy cries too. I scream during showers and mummy will just run out of the shower and i knew that she went to cry. My parents are both working but they never have any savings because both my brother and i are special needs children. Mummy always wish i can score well for PSLE but this year she told me its ok if i cant make it. She said im already an express student to her. I want to help her. I know she cannot pay for my medical bills. Please help us.