she says that i just need a bigger filter
I'll be blunt: Following her advice will get you killed.
Breathing air compressors are designed to work with much different oils. The combination of compressor design and lubricant is intended to prevent harmful byproducts from being formed inside the compressor that WILL NOT be removed by the breathing air filtration designed for breathing air compressors. Even then, improper operation and maintenance can cause the output to be dangerous. This is one reason we all test our compressors' air periodically.
August Industries, Ray Contrera (compressorstuff.com, I think), Nuvair, and others sell compressors designed to make safe breathing air. They are much more expensive than what you bought. If you will breathe the air, they are worth it. For one thing, if correctly operated and maintained, they won't kill you underwater. Unless you plan to dive a lot, mix your own gases, or both, it is likely that buying fills wherever you go will be less expensive on a lifetime basis than buying and maintaining your own compressor.
Treat this as a life lesson. Keep the compressor for PCP or paintball, give it way, sell it, or return it, but don't use it for breathing air. If you do, we will read about you in the Accidents and Incidents forum. We do not want to do that. Instead, we want to read about the cool dives you did.