I just realize I will not be able to meet you tomorrow. Perhaps I can reschedule with you next week. I am sorry abotu this.
最後那句話「你都可能唔記得我同你的約會...」最好就唔好講啦。易地而處,有個人約了你明天,今天才話唔來得,仲話你都可能係唔記得約咗佢,你會點感受。感覺係「惡人先告狀」。我係佢就會話「Sure」,下星期你約定了後當日我才致電給你:I am not able to meet you today. I'm sure you don't remember this appointment anyway, so it doesn't really matter then.
口語化D可以唔好禁formal .....I am sorry to say I can't come for the meeting tomorrow, do you mind make it next week, I bet you have also forget our meeting ha ha.