The pain when it strikes at full force is so shatteringly powerful that it’s hard to believe the blast is contained within my own body. There ought to be a flash of blazing light as it explodes, debris scattered around its perimeter. Yet not even my face shows a visible sign of damage beyond, I assume, a grimace.

Eventually, an MRI scan will reveal a lesion in the relevant area of my brain, but for the moment it’s up to me to report my symptoms to the triage staff at the hospital with whatever similes I can find. It’s like being burned. Flayed. Slashed. The slightest breeze against my skin is torment.

I’m told that this particular form of pain is called trigeminal neuralgia. Dr Google tells me that it’s also known as “the suicide disease” because of the high number of patients who take their lives to escape the anguish it inflicts. My real-world doctor tells me it’s the worst pain that there is. In my case, it’s a symptom of remitting-relapsing multiple sclerosis, a disease that ebbs and flows but never entirely disappears from my life. During relapses it has blurred my vision, detached limbs from my central nervous system, tumbled the world upside-down into vomit-ridden vertigo.

During remission, life is more than tolerable, if hard work. My balance and physical strength have been eroded and something always hurts if I pause to take an audit. All the same, I remain in paid employment and I share my life with a funny and resilient teenage daughter. I try not to think too much about the future and all the unpleasant possibilities it may hold.

I understand why some patients with multiple sclerosis say they want euthanasia, rather than enduring protracted physical pain, decline and dependence, to be an option. I have no trouble visualising scenarios in which I ask my health professionals to assist my suicide – in fact, I have to battle to keep such visions at bay. But if and when I reach that point, I want those who I may ask to be legally obliged to refuse me.

I do not believe it is appropriate for the state to determine that the desire to end one’s life is in some circumstances a symptom of depression to be combated and controlled and in other cases a rational decision. Advocates for the legalisation of euthanasia stress that they have no intention of making it compulsory. Since they do not plan to impose their beliefs on me, I am not entitled to impose my beliefs on them.

However, I do not believe that legalised, state-endorsed euthanasia would be an autonomous decision, either in terms of the circumstances in which it is made or in terms of its consequences for others. The social stigma attached to diseased and disabled bodies would both shape euthanasia decisions and be reinforced by them. Even those who would not themselves choose to make use of access to euthanasia would have their lives devalued by its availability to them. How “voluntary” would voluntary euthanasia be in a society that stigmatises physical impairment and dependence, and which regards ageing as decline rather than accumulation? Does a society that tells patients there is a months-long waiting list for an appointment with a pain management clinic – as I was told during my most harrowing struggle with the suicide disease – have any business legalising euthanasia under the banner of autonomous choice?

Euthanasia advocates point to opinion polls indicating very high levels of public support for their case. However, based on my own admittedly unscientific but nonetheless extensive straw-polling, I think this reflects an instinctive recoil from the horrors of drawn-out death rather than an informed and considered position. There is a widespread assumption that those opposing euthanasia do so because of their adherence to conservative religious values. The disability rights perspective is not well known. Once it is expressed, support for euthanasia becomes far less adamant.

Many of those who initially support legalised euthanasia also believe that its opponents would require doctors to preserve life at any cost. But opposition to euthanasia is not the same thing as demanding futile and painful treatment regardless of consent. Some treatments may help to extend life at the cost of adverse and unwanted side effects that may be more unpleasant than the underlying disease. To impose these side effects without consent is assault. Withdrawing treatment may hasten death, but where the intent is to improve the quality of what life remains, it’s an option that patients may justifiably choose. The same general principle applies to pain medication used to enhance life at the expense of shortening it.

Advocates of euthanasia should not assume that euthanasia would be legalised if put to a ballot. In 2012, a proposal to legalise doctor-assisted suicide in Massachusetts was narrowly defeated after a well-organised disability rights campaign under the slogan “Second Thoughts”. As disability activist Ben Mattlin wrote in The New York Times: “I can’t help wondering why we’re in such a hurry to ensure the right to die before we’ve done all we can to ensure that those of us with severe, untreatable, life-threatening conditions are given the same open-hearted welcome, the same open-minded respect and the same open-ended opportunities due everyone else.”

There is certainly ample room for reform on the issues of disability and end-of-life care. More widespread use of and respect for advance-care directives would provide patients with the higher degree of control that some currently believe would only be possible through the legalisation of euthanasia. With all this in mind, I ask Australian supporters of the legalisation of euthanasia – in particular the Greens, for whom this is party policy – to follow the lead of the voters of Massachusetts and have second thoughts.