Need advice on my weight?

Hi im just wondering if this is normal, i feel very alarmed and insecure about some recent weight gain ive had. I stopped growing when I was about 15, I was about 59kg. My weight fluctuated within a couple of kgs but I recently started my final year of high school and have been studying a lot more, snacking, less exercise. I went on the scales the other day and i now weigh 69kg. I burst out in tears, I feel horrible and as if my body is out of my control. Is weightfluctuationn around this age normal??? I am vegetarian also, I do not eat too unhealthily.