We appreciate your concern.
Thanks for your concern.
Thanks for being concerned.
Thanks for your concern.
Thanks for your concern.
Thanks so much for your good thoughts.
Thanks for letting me know.
気にかけてくださり、ありがとうございます。
It is very thoughtful of you. Thank you.
Thank you for your commiserations.
Thanks for worrying.
Thanks for your concern.
Thanks for keeping me in your thoughts.
Thanks for your interest in me.
Thanks for caring.
Thanks for keeping me in your heart.
I am much [greatly] obliged to you for your trouble.
Thank you for your kind advice [suggestion, warning].