I really wish people would stop using the 'forget about her' card.
If you have to see her often, it's pretty fucking hard to forget about her. I was in the same position with a girl at University.
Hell, even if you don't see her often, it can be pretty fucking hard to forget about her. I haven't seen this girl since 2014 and I still dream about her sometimes. I'm now forced to live the rest of my life in regret for asking her out by a fucking text message (which she read, but never replied to). That's pretty fucking difficult to forget.
It's the only realistic option.
Forget about her, and accept your forever aloneness. Don't be like me.