HI!
If you want to use "I" in your main sentence, you can say:
I'm sorry (that) I took your time.
(I'm sorry if I have taken your time.)
I found these explantions:
Sorry about: در مورد اتفاقی که افتاده/ وضعیتی که پیش اومده
You feel sorry about something that has happened.
"I am sorry about your results."
"I'm sorry about the loss of your father."
You may also feel sorry for /about something that you have done. اظهار تاسف یا معذرت خواهی بابت کاری که خودتون انجام دادین
"I am sorry about disturbing you."
"I'm sorry about the mess."
"I'm sorry for taking / having taken your time."
"I am sorry for ignoring you.".
Sorry for برای فرد دیگه ای ناراحت یا متاسف هستید
You feel sorry for a person.
I feel sorry for him.
http://www.englishgrammar.org/
http://www.english-online.org.uk/adv3/sorry1a3.htm
PS:
1:
I'm sorry to... بایت اتفاق بدی ناراحت(متاسف) هستید
"I'm sorry to hear about your accident.".
"I'm sorry to say Joey's aunt died yesterday."
2:
I'm sorry to take your time: ببخشید که وقتتان را می گیرم
I'm sorry for taking your time: ببخشید که وقتتان را گرفتم