en_tn_condensed/isa/38/15.md

What shall I say?

Hezekiah uses a question to emphasize he has nothing left to say. This can be written as a statement. Alternate translation: "I have nothing left to say." (See: rc://en/ta/man/translate/figs-rquestion)

I will walk slowly

This is an idiom. Here "walking" refers to living. Alternate translation: "I will like humbly" (See: rc://en/ta/man/translate/figs-idiom)

all my years

This refers to the rest of his life. The meaning of this can be made clear. Alternate translation: "the rest of my life" (See: rc://en/ta/man/translate/figs-explicit)

because I am overcome with grief

"because I am full of grief" or "because I am very sad"