I'm trying to clear my mind of all this.

我正试图把这一切都从我脑子里清理出去。

《柯林斯英汉双解大词典》

I wish I could clear my mind of doubt.

但愿我能消除心中的疑虑。

youdao

Reading this made me aware that I wasn't very clear in my own mind about the meaning of forgiveness.

阅读这封信让我意识到其实我自己对宽恕的意义也并不很清楚。

youdao

In the beginning I thought a two year tenancy was way to long a time but now am thinking clear and my mind is adjusting to a new way of life, I can see now why two years isn't such a long time after all.

BBC: Coming Clean: An addict's diary