Dear my friend,
It is great to have you in my life for helping me both in my study and in my personal affairs. I have to say thank you from the bottom of my mind. You were so nice to me and so helpful that I could not even overcome any of the difficulties that I have encountered without the assistance from you. Please accept my sincere appreciation for what you have done and I will definitely cherish the friendship we have.
Wish you all the best.
Regards,
XXX