Should I tell a straight girl that I have/had a crush on her before I graduate high school?

i've made a youtube account for the exact thing that you're asking right here. for some reason it doesn't let me post the channel on here so type in lawlzxobriiiiful on the youtube search bar or you can type it in on google its on both places and i think it can really help you ! if you like the videos you can message me on youtube or e-mail me on here and i'll answer ASAP :D