I kept telling myself to keep calm.

我不断叮嘱自己要保持冷静。

《牛津词典》

I kept telling myself (that) everything was OK.

我不住告诉自己一切都没问题。

《牛津词典》

At least, that's what I keep telling myself.

至少，那是我一直告诫自己的。

youdao

"I keep telling myself: It's going to be OK, " she said.

CNN: Crews go on offensive against growing Colorado wildfire

For me, I keep telling myself, I say it's all right.

CNN: Interview with Jack Neo

My internal dialogue seems to be less focused on telling myself I can't do it and more concerned with developing and executing a workout exit strategy.

CNN: Work out what matters most: Your mind