What to do when groomers refuse to work on my cat?

I have a very fluffy cat who hates getting groomed. He’s had lion cuts before but since moving to California I have tried to take him to 7 different groomers and they all call me back about 20 minutes in and say they won’t groom him because his stress level is too high. I don’t know enough to do it myself so I’m at a complete loss about what to do. He’s starting to get matted because he hasn’t been cut. What should I do??