So the SSI denial has nothing to do with the shack you own, nothing to do with whether or not you are disabled and everything to do with the amount of savings you and your wife have that is over the $3000 resource limit.

If you are able to get a job and haven't worked in 12 years, if you do manage to earn 4 quarters a year for the next 5 years, and you have 10 years of work in your lifetime, you would then have enough credits for for Social Security disability and could still keep your $21,000 in savings since it would be Social Security and not SSI that you'd be applying for. The monthly amount might not be very high because your lifetime earnings, including the zero years, are all factored in.

A minimum wage job, 20 hours a week for the next five years might just be enough. You'll then also be over 50 and it may be easier to qualify.