You are not disabled.
If you are living unmarried with your partner, you are single, and file a tax return using single status. (Or, if you provide care in your home for a qualifying child dependent, you might be able to file as Head of Household.)
Either way, you list your income and deductions. "You" in the program refers to you, not your partner.
Your partner might qualify to be claimed as a tax dependent, and if so, you can check the box in the dependent information section that your dependent is disabled. But "you" are not dependent.
Separately, the tax definition of "disabled" is "unable to perform gainful work due to a condition that is permanent, or will last at least one year, or will lead to death." Many people who meet the definition of disabled for other purpose, but who can still perform "gainful work" are not disabled for income tax purposes. For example, many "disabled veterans" can have service-connected disabilities like amputations, and qualify for VA benefits, but can still work at normal jobs (with accommodations) and so are not disabled for tax purposes.
