从那以后 from there here after.... 自那以来 since...then... 差不多两年前, (自从) 我看了这个音乐录像(以后), 我迷上( 了) 力宏! Traditionally, Chinese teacher(s) who crossed out or add some words to the sentence, making the sentence sounds better. Here, the words in ( ) are the words that I will placed in the sentence. Just for your reference, the arrangement of these words is the matter of personal preference. No right or wrong.

there's no difference,and your sentence is correct!! besides "自那以来" "从那以后"，you also can use "从那时起" "自那时起" " "自那以后".

从那以后

从意思理解上讲，两种讲法都是正确的， 但我们通常用的是“从那以后”。你可以这样写“大概两年前我看了这个音乐录像，从那以后我就迷上了王力宏。”

两句话表示的意思都是一样的！ Got it？