Many. Figure of speech Anaphora.
my soul. me, or myself. Hebrew. nephesh. App-13.
help. salvation, or deliverance.
God. Hebrew. Elohim. App-4.
Selah. Connecting the contrast between "man" (as. creature) who knows God (Elohim) only as Creator, with the speaker (David), who knew Jehovah as his Covenant God. See App-4 and Psalms 66:11.