On in

On in
 

p.197
-From here on in, I may be as [...]

What does IN mean?

This is a set phrase. It means 'from now on', until a certain time.

From here on (from this point forward)
From here on in (from this point until a specific event has occurred)
From here on out (from this point forward, with no end)

These are mostly interchangeable, but 'from here on in', at least to my mind, has an end.

Good answer. Thank you.