She's just a girl. If a girl taking an interest in you seems like a sign from above, then I'd say you need to examine what you think a relationship is. Take her off the pedestal. She's a person, not an angel.

Unless she was mean to you in some way I haven't picked up on, she doesn't seem like a bad person. Getting friend-zoned is not a malicious act. Her not having the same feelings toward you, but wanting to be friends is not the worst thing in the world. She seems like a real friend who helped get you through a tough time. Is/was she your "friend" or a "mere acquaintance"?

Placing so much universal significance on a "mere acquaintance" tells us about where you place your self worth. I'm sensing that you need to get on good terms with yourself. So focus on that for a bit. Get some confidence and get back in there!