From your truth-table it should be clear that you expression should not equal $0$ ... and by the way, your expression right before $0$ equals $1$, not $0$ .... but the truth-table also makes it clear it is not $1$ either. So, something clearly went wrong ...
Here is your mistake. You went from
$\neg (A \lor B \lor \neg C) \lor ....$
to
$\neg A \lor \neg B \lor C \lor ....$
You applied DeMorgan correctly from line 1 to 2, but did not apply it correctly from line 2 to 3 ... indeed, you'd just get back to line 1 if you were to apply it correctly.
Now, as far as simplifying your statement goes ... note that in every case that $C=1$, the expression evaluates to $1$ as well. So, all those rows in the truth table can be captured by just $C$. The only other case is the $\neg A \land B \land \neg C$, so you can immediately simplify the statement to
$C \lor (\neg A \land B \land \neg C)$
which further simplifies to
$C \lor (\neg A \land B)$