I am going on losing weight after shifting to hostel. Shall I take some supplement?

Hi doctor,

I am doing my college first year now and living in a hostel. While in my home, my health was good and I had even joined a gym for bodybuilding. After going to hostel, I only ate food given in the mess and sometimes, snacks from outside. After two months, I returned home and everyone was shocked as my weight has reduced and even my face had shrunken. Now it is five months after joining college that I am back home and my condition, according to family is worse than before. I cannot expect my hostel mess to serve me rich food to gain weight neither I will have the money to buy eggs, fruits and milk from outside every day. So, I was thinking to go for some mass gainer or protein powder supplements as I also wanted to resume my workout, which I have not started here because of my deteriorating health. So, I wanted to consult whether I should buy some supplement. Also, advise me the product as I am really worried about my weight.