I have been asked by someone to translate this letter they received. I have made an attempt at some of it but not really happy with it so would be grateful if someone more expert could do it for me here. 
Kýymetli xxxxxx, Dear/Esteemed xxxxxx,
Sen hala beným için bulunmaz bir arkadaþ, bulunmaz bir dostsun. Her zaman için senin gibi bir dostun kalbimde doldurulmaz bir yeri var. Senin gibi bir arkadaþa bir dosta herzamankinden daha çok ihtiyacým var. You are still for me an undiscovered friend. An undiscovered close friend. There is always an unfilled place in my heart for a friend like you. I always have a need for a friend, a good friend like you.
You are still for me a rare friend, a rare close friend. There is always an unfillable place in my heart for a friend like you. I need a friend like you much more than ever.
Dil öðrenmek ise tabiki o da ayrý bir ihtiyac. Ama kaybetmeyi göze alamadýgým bazý deðerlerim var. Biliyorum çok anlayýþlýsýn, hiç þüphe yok. Ama bunlar farklý. Yalnýz senin deðil, bir çok insanýn, hatta bir çok Türkün bile, bilemedigi ve anlayamayacagý seyler. Keste sana anlatabilseydim. Neyse.....
To learn a language of course, that is another necessity. But (losing??) that I took a risk is sometimes valuable to me. I know it´s not a very super explanation. But these differences alone are not yours......................................................and I am not able to explain things. If only I was able to explain. Anyway....
To learn a language of course, that is another necessity. However, I have some values that I cannot risk to lose. I know that you are very comprehensive/considerate, there is no doubt. But these are different/hard to explain. These are things that are hard to know and to understand for not only you but for a lot of people, for even many Turks. Anyway....
Borçluluk konusunda düþüncelerin beni duygulandýrdý fakat ben senin gibi düþünmüyorum. Bir þeyin karþýlýðý veriliyorsa ya da karþýlýk bekleniliyorsa, o iyilik deðil alýþ veriþ sayýlýr. Halbuki iyilik karþýlýk beklenmeden yapýlan yardýmdýr. Ben yanlýzca iyi kalpli bir dostunum. Bana ihtiyacý oldugunda dostumun yanýnda olmanýn mutlulugunu yaþamýþým. Bence kýsýtlý imkanlarýmdan dolayý, az bile yaptým.
Your thoughts about being owing to me touched me but I don´t think as you. If a return/compensation is given or expected for a thing, then it is not considered as a favor but a trade. Whereas a favor is a help being done without expecting a return. I am just a goodhearted buddy of you. I have lived the happiness of being beside my friend when he/she needed me. As for me, because of my limited opportunities, I did not do enough.
Mutluluk sana layýktýr The happiness you deserve
You deserve happiness.
Mutluluklar senin olsun Best wishes to you
Let be all the happinesses be yours.
Ne zaman ki bir dosta, bir arkadaþa ihtiyaç duydum. When a friend needs a friend I am aware
When I needed a friend like you,??? It seems like something is lacking here.
Hep seni düþünüp hep senin hayalini kurdum. I always think about you, always put up with your faults (???)
I have always thought and dreamed about you.
Seni hic kimsenin eriþemeyecegi yere, yüksege koydum Nobody can reach the high place I put you on.
I put you somewhere, to a high place that nobody can reach.
Her yerde seni aradým hep seni sordum. I looked for you everywhere, I always asked for you.
I hope it helps ladyinred. You can correct the english mistakes and make it sound more english.