根本不知道英语

Definitely you do not know the pain of my heart. Definitely you do not know how much my heart hurts. never 是 从来不，表达“根本”要用 definitely。ache：痛，但是用于病理方面。pain: 可以表示精神上的痛苦。

I have no idea 或者 I don't know

you never knew how my heart aches.you never saw the tears of my heart.

You don't know my heartache at all.