You are juggling numbers, it never helps.
You have to calculate number of mmoles of acid in the final solution, and number of mmoles of conjugate base in the final solution, to plug them into
Henderson-Hasselbalch equation.
How many mmoles of acid were present initially? How many were neutralized? How many were left?
How many mmoles of the salt were present initially? How many were produced during neutralization? How many in total?
And please - don't cut corners. Answer every of these questions separately and list your answers. Otherwise we can't show you what and where you are doing wrong.