Perhaps you should find out what problems the doctor(s) think naloxone would cause for someone with your condition. Perhaps they have good reasoning that you aren't aware of (or maybe they are just brushing you off).
I can't help thinking that if you are on medication that poses such a grave risk to your survival, that maybe you are on the wrong medication. Have you tried using patches? I just thought that as the dose would be not only smaller but more even from hour to hour, without peaks and troughs in drug levels, it may be less likely to trigger an adverse reaction. And seeing as the blood levels are so low, if you did have an adverse reaction, once you take the patch off, your levels would reduce quicker than from oral medication.
With oral medication, you spend a lot of time at sub-optimal level of drug concentration and above-optimal levels, with less time in the middle, at the level that you require for pain management. Obviously this would not be good for someone with your condition, as the fluctuation in levels complicates your body's (already erratic) response.
As for getting naloxone from a doctor, the more you give the impression that you know what is best for you, the less doctors want to give it. They like to feel they came up with the idea.
Tip: don't tell the doctor you have an allergy to opiates, it is an adverse reaction. An allergy would mean you have an anaphylactic reaction any time you take opiates. Whereas what you are describing are exaggerated side effects. Calling it an allergy is a surefire way to get the doctor to think they know better (it's a pet hate of health professionals).
Tip 2 : You won't get a good response going to the emergency department for a prescription that should be handled by your normal GP or specialist. You don't want to get a bad reputation, and some of the ways you are approaching your requests will mislead the doctors into getting the wrong idea about you.