Hi rdut,
It's not too bad, there are 2 spots marked wrongly in the red are I marked. If you correct those, and the logical follow up you made in the same columns, I think you should be ok

As far as I can tell to the left of column 24 in the black are you marked there are no mistakes, so you don't have to delete that whole area.
I hope you can finish the puzzle now. Request for you, if you manage to finish it, please let me know so I can delete the almost finished picture of the puzzle so it won't spoil the solving pleasure of future solvers

Good luck, Maarten
edit: picture deleted