Cannot afford fiancees medical expenses, so... Legal marriage or commitment ceremony?

My fiancee has many health issues, including diabetes. She's an "agent orange baby". She has 16 prescriptions and a number of specialists. She's currently. on medicaid, which covers 100% of all her prescriptions and 100% of all her other medical expenses.
Once we marry, she loses this. On the insurance market, prices are absolutely terribly high, even with subsidies. My insurance is way better than most options on the market; but still has minimum prescription costs, deductibles and all that other stuff.
End result is that her expenses could easily cost me over $400 a month. I can't afford this. Her disability check barely covers all her other expenses and she cannot contribute.

So... If we have our wedding, we go through everything, except our officiant does not turn in our marriage license. Nobody knows the marriage is not legal, except for us. Not being "legally" married allows her to keep all her benefits. We wear our rings and she goes through the legal process to get my last name.

I'm a traditionalist and want the legal wedding, knowing this could bring us to total financial ruin. But I understand the fake wedding is the logical choice. She is good either way, but is supportive of my choice to. prefer the legal wedding.

What should I do? Thanks!
Updates
+1 y
Update; we will have a legal wedding.
Cannot afford fiancees medical expenses, so... Legal marriage or commitment ceremony?
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