Many including myself have been facing this since forever. It is called being thrown in a higher level competition and it is one of the main things I hate in this game. Your opponent is aware of this and probably manipulated the draw, this gives him obvious advantage and he probably is going to win. You can search on this forum about manipulating the draw tips, basically you need to sell some players to lower your team quality at the end of the season. I have resisted doing this but there is no other way really. Even in my cup all the quarter finalist are plus 1 higher level teams.