Try to find someone in your area who specializes in endometriosis surgery. A lot of the tissue that has travelled to where it should not be inside the abdomen can be removed, if you find a good surgeon who can identify it successfully (a lot of times a regular ob-gyn who has not specialized in this will miss the cues and leave some of it behind.)
The only way I would advocate that is if you have already had all the children that you want. But otherwise, no way. I've had endo for years. It's unpleasant certainly, and at times, quite painful. But a hysterectomy is pretty drastic. But if you are sure you're done having children, then I guess it's worth considering.