Should i let him know?

I was writing him a letter, telling him what matters me when i said it doesn't matter last time.
Wondering is it a good idea to disturb him again. He seems to go on his life normally.
should i? If i really care about him, i shouldn't tell him right? I should let him go.
But how if the letter can clear both of the doubts between us?
Or at least help me to go out of the mess.
Should i?

I wanna sleep...so tired.