Hi!! It has indeed been a looong time. :-D
If you want to say that in German, then you should say it like that: "Es ist sehr lange her" x3 What you wrote means something like "I've missed you", but "verfehlen" is not the correct word lol. I rather think that the word you wanted to use is "vermissen", right? xD
I've been good =) What about you? What have you been up to?
<3