I love somebody more then you can imagine but she does not feel the same for me (sorry this post is so long lol)

I have loved the same person for almost 8 years. I do not mean just like a crush or attraction I mean i seriously love this person. I am willing to do just about anything for her and I find her to be physically beautiful and to have a very amazing personality and way of living. But that aside I will tell a bit of a story...

I hardly talked to her beyond the 4th grade, we would occasionally speak but not often, during this time coincidentally we both had feelings for each other but this is somewhat irrelevant now.

In the 10th grade, i still had feelings so i went to speak to her, i started texting with her often and we had a decently friendly relationship however i acted very immature and made some poor decisions, nothing horrible but enough to make her feel unattracted to me and lose any chance of being with her that I had. This was a very important event in building who I am today. I realized that because of the way i acted, she had gone from being interested in me to be completely done talking with me in just a few weeks, i lost the chance i had to be with the person i loved for so long and that really hurt me.

Because of this i began to change myself, around a year later i tried talking to her again but i was pretty much just a bother and she ended up blocking me on socials and It was somewhat deserved in all honesty. Throughout all this time my feelings never changed though and she was still on my mind 24/7 and i thought about her everyday all the time no matter what.

now fast forward to the present, I am at the start of my 12th grade year and she sits near me in one of my classes, in my mind this could be the final time i ever get to connect with her for the rest of my life, and so this is big for me. I have still yet to even say hi to her as it just feels nervous and awkward because of the past.

I also want to clarify I did date somebody else during this time but throughout the relationship i ended up still constantly thinking about this girl and even comparing my girlfriend to her very frequently, honestly my conflicted feelings ended up causing the downfall of this relationship which was sad. but also to me showed that my feelings were genuine and I really love this girl.

I want nothing more then to be with her, and while many people have told me i should just move on and leave her alone, not only does this seem like an impossible challenge it would also just be really sad because many people try their whole lives to love someone like this and i actually get to feel it right now. I am unsure i will ever feel for someone the way i feel for her, specifically because i tend to be a fairly judgmental person but yet i still see this girl as flawless and amazing.

Any advice is appreciated!