Dear [Name],
I just wanted to take a moment to thank you for all of your hard work and support. Your kindness and generosity have meant so much to me, and I really appreciate everything you have done.
Thank you for being such a wonderful friend and for always being there for me. I am so grateful to have you in my life and I am truly lucky to have such a wonderful person in my corner.
Sincerely,
[Your Name]