暗恋你好久了可以用以下几种英文表达：

1. "I've been secretly in love with you for a long time."

2. "I've harbored a crush on you for quite some time now."

3. "You've been in my thoughts for a long period of time."

4. "I've been in love with you without you knowing it for ages."

5. "My feelings for you have been growing stronger over time, even though I haven't told you."

希望这些表达能帮助你传达你的情感。