Okay, this is probably a dumb answer, and may not apply to your problem, but early on I was having similar problems. Parts were mirrored, words were backward, etc.
I had used a manual mill but never had been exposed to cnc. I was used to zeroing everything from the back, right hand edge of a vise and set up my small cnc mill with the same orientation. Was going through a lot of gymnastics to cut things cut properly. One day I had a BFO (Blinding-Flash-of the the Obvious. CNC climb milling is oriented opposite. When I re-set my axis to run that way, my problems went away. I may still be wrong, but my parts come out correctly and I don't have to read my engraved words in a mirror in order to make sense of them.
The cad programs I have been working with have the X - Y axis orientation located in the bottom left hand corner. You mill should be set up in a similar manner.
Stand in front of your mill and use the left hand thumb, index, middle finger visual to see which way your mill is running. (thumb pointing up (for the Z axis), index finger pointing away from you (indicating Y+ movement), middle finger pointing to your right (indicating X +)
If that doesn't solve your problem, I was either wrong, or you have another problem. Good luck.
Anyone with a different (and maybe correct) solution should feel free to jump in and correct me.
Bob @ BobsShop