Should i confess??

I'm just really looking for an advice,(I'm not sure tho if this is the best place to ask.)
So I have a crush on someone for 3 years now. 2 years ago, we were classmates and we always talked to each other, mostly about anime and movies. But for the past 2 years i had never exchange any words with him since we aren't classmates anymore, we don't even share eye contact since we rarely see each other. But every day I just realize that I truly love him.(even if sometimes I suspect it's just my attachment issues). The problem here is:
1. He's taken.
2. We both have like this big exam at the end of the year, that will decide our future. I'm afraid if i got in any sort of relationship i will be distracted, and will fail.
3. Even tho we were kinda close?? We stopped talking (mostly my fault because I'm really shy and whenever I wanted to greet him or talk to him outside I find him with his friends anf I get anxious)

So, really what you'all think I should do??