What is the ruling on slaughtering the animal entrusted for sacrifice before the Day of Sacrifice, and is the Hajj valid, and is a new sacrifice obligatory, and is it permissible to appoint someone to slaughter in Makkah these days?

The best time to slaughter the Tamattu‘ offering is on the Day of Sacrifice (Yawm al-Nahr) after stoning Jamrat al-‘Aqabah, as the Prophet, peace and blessings be upon him, did. Scholars have differed regarding the sufficiency of slaughtering before the Day of Sacrifice, and there is no explicit evidence to support either opinion. Therefore, as long as the slaughter was carried out as you described, there is no sin upon you and you are not required to offer another sacrifice.