Dear [Name]:

I am writing this letter to express my heartfelt gratitude and appreciation for everything that you have done for me. Your kindness, generosity and support have helped me achieve so much, and I don't think I could have done it without you.
I remember when I was going through a tough time in my life, and you were the first person I turned to for help. You listened to me when I needed to talk, offered me encouragement when I was feeling down, and helped me plan a way forward. You showed me kindness and understanding when I needed it the most, and for that, I will be forever grateful.
As I move forward, I will never forget the support and guidance that you have given me. Your valuable advice has helped me shape the decisions I have made and the path that I have chosen. You have inspired me to be a better version of myself, and to strive for success in everything that I do.
Your unwavering support has not only helped me achieve my goals but also given me the strength to face any challenges that come my way. You have always been there for me, through good times and bad, and for that, I will always be grateful.
Once again, I want to express my gratitude for all that you have done for me. You are truly an amazing person, and I am lucky to have you in my life. Thank you for being there for me, and for being such a wonderful friend.
With gratitude
[Your Name]