Friendship

I have this friend who has been my rock through all of this. I treasure this friendship. I would be lost without it. This friend has been my sounding board, a shoulder to cry on, someone to vent to. All the while not asking anything back.
How do you let someone know how much they mean to you? You can say it a thousand different ways, show it a thousand different ways and still wonder if they actually know their worth to you. I am so thankful for this friend.
Thank you.