Question

رشته افکارم پاره شد

Answer 1

 I lost my train of thought. 

See 

http://idioms.thefreedictionary.com/lose+train+of+thought

Answer 2

He disrupted my train of thoughts!

She interrupted me!

Answer 3

I was distracted.

My concentration was shattered.

Answer 4

Hi

Similar:

Oxford: 

lose the (or one's) thread 

Be unable to follow what someone is saying or remember what one is going to say next:

she lost the thread of the conversation after a time. 

You've made me lose my thread.

Answer 5

اگه تو فکر یه چیزی هستید و یهو ذهنتون بره جای دیگه

 فکر کنم همون

i've got lost

i lost attention