Have you properly considered for your case the pros and cons of CP as an alternative? If you need to work and spend time with your dad and get a green card as soon as practicable, even with late submission of DS260/change to CP it might make sense in your case to spend a couple months in your home country doing all this than sitting around in the US. Might - because I have no idea of your specific situation, any potential for AP etc.
Would you know if this would apply - Would it still be possible to work on the O-1 for the allotted 240 days during the time of petition/processing for the AOS?
Long shot, but it kinda makes sense to me, in my simple understanding of the Opaque US immigration system...
O-1 Visa
If you would like to extend your O-1 status, the United States Citizenship and Immigration Service (USCIS) will determine the time you would need to accomplish your work in increments of up to 1 year.
You must submit proof that your employment is ongoing, and you generally must include updated evidence of your extraordinary ability. A petition must be filed before your current O-1 status ends in order for you to maintain your status and remain on payroll.
If a petition is filed in a timely manner, you will be authorized to continue to work and be paid for up to 240 days after your current O-1 status expires.