What am I doing wrong? ?

Why do people I love always ignore me, or refuse to reply to my emails/texts when I make my feelings for them so clear. I am a really straightforward girl, so if I like a guy, I would find various way to let them know that I like them. But the guys I really like will always ignore my emails or my texts...It is devastatingly hurtful when that happens. Am I creeping them out? Am I causing them to lose interest by showing interest to soon? What should I do?