"sana asik oldugum yada seni geri istedigim için yazmadin

bunu isteseydim zaten senden ayrilmazdim

ben sadece eski bir dostu özledim hepsi o

mutlu olmana sevindim"

My attempt. I am not a native speaker, I think this is the general idea.

"I became very filled with passion for you also that because I wanted you to come back I didn´t write.Anyway If I wanted that  I would never leave you.  I merely missed an old friend,  for all of your happiness I was delighted."

I didn´t write to you because I´m in love with you or because I want you back.

If that was the case I wouldn´t have left you.

I just missed an old friend, that´s all. It´s good to hear that you are happy.

Thank you a lot Erdinc