Here is a suggestion for your last paragraph:
After my mother's death, there was little money, which has made for financial stress for the family. My father is very old and retired. I still have to study for 2 more years. Fortunately, my sister has graduated and has work. My father sets aside a little money for my tuition. For myself, I have to live using only 100,000 Bath for 2 years. When I am able, I do part time jobs such as photography, event runner and freelance typist to earn extra income.
I still want to study aboard to increase my knowledge. If I get financial support from the university, it would be helpful. Moreover, if I could go to study aboard at your university, I can work a part time job for extra income to buy educational needs and personal things. Since I have earned my own living by myself for the past year, I am sure that I can work part-time and will be able to help support myself. I need assistance to pay for tuition and housing costs.