Hi there and welcome. You have come to the right place.
As others have stated if you have been making the proper adjustments and not getting results it's time to do a capkit and possibly change the flyback. I have seen monitors look better than I could have ever imagined after a capkit, flyback and proper fine tuning adjustments like b+, color, focus, brightness, and convergence.
If I was you I would do a cap kit and replace the flyback.
There is a model number you will most likely find on the chassis frame or on the chassis PCB. With this information you can order the proper parts.
Peter Mortel from
www.arcadepartsandrepair.com has been invaluable in helping me out and has all the parts you need. KLOV user: security0001. You could also send him pics of the chassis if you can't identify it.
In addition
www.iankellogg.com is another popular place to get capkits because of how his kits are setup and labeled.
If you don't already have, you will need a soldering iron and a cheap solder sucker. You can find these on amazon and check back to this post for confirmation of parts if you have questions.
Lastly if you don't feel comfortable doing the work yourself there are plenty of nice and reputable folks here on KLOV that you can pay to do the repairs.
With a little searching you should be able to find most everything you need.