I don't think your crazy.
I think you met a way to cope under the circunstances you were facing. It's good that you found in yourself what you needed to superate your dificulties and feel happy.

But, as you may know, your boyfriend is your imagination giving you what you emotionally need and want, what probably you desire. Trying to repress the need of a boyfriend made you think more about having one and it probably made this happen.

Just don't forget this isn't real. College is hard, I too feel very sad when I have a low grade. But you have to understand that it don't make you a lesser person and you have to let it go. And you should go to your friends again, they can help you fill the void you filled with your imaginary friend.

I think that along the way I have created some imaginary boyfriends too, they just had the face of real boys I knew. I let them go when I realized that person wasn't real and that it wouldn't ever happen in real life. And I learned I had to appreciate myself as I am, like me the way I am and give myself the emotional support I needed looking to my problems in prespective.