I know that I can never have someone, but I also know that I may never get over her because of how deeply I have been in love. We have known each other since childhood, and she told me that we could never be together because she can never see me as a romantic partner. I believe the opposite to be true because we know everything about each other. I don’t know how I am supposed to go through life facing the possibility of her being with someone else. I don’t even date other women because none of them match up to her in my eyes. I feel as if I will always be alone because of this. How do I cope?
You have expressed yourself and received a response. You can choose to accept that someone else’s life is not in your control or spend your own life obsessing over the past rather than your present or future. To assume that you will never find someone who matches this ideal person is naïve, even though it may not seem like it yet. Why not go out without expectations, meet people, and accept that perspectives change as we grow older? You may surprise yourself sooner than you think. Your pain is real and may take time to manage, but it may ultimately give way to something more meaningful.

Should I stay with my boyfriend out of spite because of a former friend who is in love with him?
This depends upon what your priorities are. If you are willing to lie to yourself and your boyfriend by being in a relationship that isn’t real, you must ask yourself who is the one being harmed here. Your spite may offer what feels like a great reason, but there is always a price to pay for something that isn’t bringing you any genuine joy or fulfilment. You are also ignoring the fact that time isn’t infinite and being with someone you don’t love prevents you from finding someone you might.