Yes, Jesus is God. But as Phil 2:7 says, as Jesus, God emptied Himself and took the form of a servant. So as Jesus, I wouldn't say He was 'omnipotent'. (However, since God is omnipresent, it's not like there wasn't someone running the universe while Jesus walked the earth.)
Philippians 2:7, NIV says nothing about "emptying Himself." I do recall that that phrase occurs in the Charles Wesley hymn "And Can it Be," second verse, "He left His Father's throne above / so free so infinite His grace / Emptied Himself of all but love /and bled for Adam's helpless race."
However, the biblical text simply says that Christ "made himself nothing."
IIRC, an explanatory text of the (I think) Westminster Shorter Catechism put it well (I think I quote it correctly): "Remaining what He was [i.e. divine], he became what he was not [i.e. humman]."
So I must respectfully disagree that Jesus lost omnipotence. After all, he did perform miracles and he did rise from the dead.