Assume the white group dies. Conservatively, let's not count the lower left corner for black due to the bad aji around 3-3. Then black's solid territory is roughly:

- Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | C C C C C . . . . . . . . C C O . . . |
$$ | C C C C C . . . . . . . . X W X X O . |
$$ | C C C C X X . . . . . . X X W X X O . |
$$ | . X X X O . . . . , . . . O X X O . . |
$$ | . . O . O . . . . . . . . O . . O . . |
$$ | . . O . O X . . . . . . . . . O . O . |
$$ | . O . X O X . . . . . . . . . . O X . |
$$ | . . X O O O O O . . . . . X . X X X C |
$$ | . X . X O X X . . . . . . . . . C C C |
$$ | . O X X X . . . . , . . . O . X . C C |
$$ | O . O . . X O . . . . . . . . . X C C |
$$ | . O . . O O O . . . . . . O X O X . . |
$$ | . . . . X X X X . X . . . . . O O . . |
$$ | . . O O O X C C . a . O . O . . . . . |
$$ | . . X . X W W C W . X X . O . . O . . |
$$ | . . . X . X C C C C . . O . O X O . . |
$$ | . . . . C X W W C X C X X O . . X X . |
$$ | . . . C C C X C C C C C C X X . C C C |
$$ | . . . C C C C C C C C C C C C C C C C |
$$ ---------------------------------------[/go]
Black has 76 points marked. There's aji around a, but black can probably hold things intact and keep the white group dead. There is some expansion potential at the top, and the potential to solidify the lower left corner.
There's a little aji in the black group, but assuming it dies, white's territory is roughly:

- Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . O . . C |
$$ | . . . . . . . . . . . . . X O X X O C |
$$ | . . . . X X . . . . . . X X O X X O C |
$$ | . X X X O . . . . , . . . O X X O C C |
$$ | . . O . O . . . . . . . . O . . O C C |
$$ | . . O . O B . . . . . . . . . O . O . |
$$ | C O C B O B . . . . . . . . . . O X . |
$$ | C C B O O O O O . . . . . X . X X X . |
$$ | C B C B O B B C . . . . . . . . . . . |
$$ | C O B B B C C . . , . . . O . X . . . |
$$ | O C O C C B O . . . . . . . . . X . . |
$$ | C O C . O O O . . . . . . O X O X . . |
$$ | C C . . X X X X . X . . . . C O O . . |
$$ | C C O O O X . . . . . O . O C C C . . |
$$ | . . X . X O O . O . X X . O C . O . . |
$$ | . . . X . X . . . , . . O . O X O . . |
$$ | . . . . . X O O . X . X X O . . X X . |
$$ | . . . . . . X . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
53 points, with 3 captures, so 56 points. So white is still 20 points behind by an estimate that pessimistically assumes white will take away the lower left corner. Importantly, black is settled everywhere, so if black can hold on to his kill (not unreasonable), and get at least one of the lower left corner and the top side (also not unreasonable), black has excellent chances even considering the strength difference.
Of course, white can deviate at some point and avoid this sequence, starting other complications. But the point is, fearing this position shouldn't be a reason to resign, because this position is *good* for black.