Is It Normal ??? I Don't Know

I have a weird habit and my habit always makes me suffer. Honestly, I feel shy to write about this habit, but I have to write it hahaha. My habit is when I meet or see someone who I really like, the condition of my body is drop. I feel weakness and slowly I get fever and flu. My habit has been there since I was in Junior High School.
Recently, when I sat next to someone who I like the most. Along my lecture was explaining the material, my body felt weakness, my heart beat was fast and slowly I got fever. So the next day, I was sick and can't entered the class. When I told about it to my friends, they laughed so hard. Until now, they always tease me. This habit makes me think, am I not allowed to fall in love? Is it normal? I don't know.