Your question made me smile. Well, having ‘feelings’ for anyone is not something in your control. Whether that person is a Muslim or not. Therefore the feelings are not wrong. What you do with them is another matter altogether. God judges us on our actions and whether the person you like is a Muslim or a non-Muslim, you are not allowed to act upon those feelings. That would be a sin.

If you are old enough to marry and think that having this crush could turn into a stronger feeling, then you need to avoid that person, pray (make dua) to God that He helps you in this situation and gets you out of it. If you are sincere in your duas then Allah will surely help you.