If it makes you feel any better- some plot lines in Charlotte Bronte’s novels were inspired by a massive crush she had on her teacher. Are you involved in any creative activities, like writing or singing? Using a creative outlet to express your feelings can be really therapeutic. If you’re not, you can just try to write a poem/song, or paint a picture based on these feelings you’re having for your professor. But if you feel that this crush is really causing harm to your peace of mind, it might help to talk to a counselor.