How can i get back into this girls life after not seeing her for so long?

It all started with a high school crush during my senior year; i sat next to this girl in study hall. She was a junior at the time; i would talk to her and ask her about her day or how things were going at the time. She was really cool; i would see her at the bus stop and when she saw me; she would approach me and give me a hug that was very strong embrace and then we would talk some more. Slowly over time i fell in "love" with her emotionally. Eventually, high school ended for me and i departed to college (university); i felt sad and had a light depression, but overtime i met new people and slowly i got over it, but i have always though about her. I would always wonder what was going on with her life or think about how far she probably is now at some college living her own life. Eventually, i transfered to another university thats in the same city that i live in (keep in mind that at this time i have almost completely forgotten about her). Then suddenly during that week that i moved back i had a dream that woke me up at 3 a.m, it was about her, we were talking and she pulled me towards her and gave me a simple kiss on the lips and held my hands. I woke up, not knowing how to confused; its like i still had feelings for her, but they were deep in my subconscious (yea i know it sounds weird, i have no other explanation for it though). Now heres the weird part, a couple of my friend goes to a community college thats not to far from where i live and i went to visit them that same week i had that dream, i go in there and i see pictures of all the teams they have. Guess who i see, thats right it her. It was weird, i was excited and sad at the same time. I felt like finding her and just telling her how i felt, but then i realized that 2 freaking years have gone by! which made me think that she probably has a boyfriend, new friends, and a new life far from that one girl i once knew in high school. I'm a sophomore in college, so she's a freshman. It's been a couple days of deep thinking, yet i'm confused. If you gotten this far into reading about my dilemma then please help me out. What should i do? should i somehow go up to her and just tell her how i feel? should ignore my feelings and hope that they just go away? I would like to start a relationship with her, but it's been so long since I've seen her that i'm not even certain that she remembers me. Any advice or words of wisdom are welcome. thanks to all who took the time to read this.