Help me! I fell in love

It was my first year of higg school and I had to change to another school since my old one was just a middle school. It all started quite usual I suppose. But before I tell you about the point where I fell in love with my upperclassman, I will give you some information about me first. I am 16-years old and I'm into anime, k-pop and gaming. However I am a clumsy and shy person most of the time and also I get lost in cities really easy... But actually I have more than this side. It's not like I have another personality within me, it's just a side which comes up sometimes but it's still me then. So the side of me that I was talking about is the not so shy side which can be a bit of a Tsundere sometimes. Actually that's the side which shows more often. The shy and awkward side is just when I have to talk to people that I don't know who are above my age... or if I would talk to someone I like. This is the reason why it took quite a while for me to become friends with my crush. But the Tsundere side of me tends to get pissed or annoyed quite easily but most of the time I can keep it to myself... I think.