Does Hajj become invalid by revoking the intention of Ihram on the first and second nights due to the unavailability of essential necessities, coupled with doubt about removing the Ridaa (upper garment), contacting one's father to return, and then renewing the intention on the way to Arafah at night?

Refusing the state of Ihram does not invalidate it or remove one from its rulings. Rather, if one commits a prohibited act, a fidyah (expiation) becomes due. The pilgrim remains in his state of Ihram until he completes the rituals or due to being prevented (from continuing) or a stipulated excuse. Removing the izar (lower garment) is not a prohibited act unless it is replaced with a prohibited garment (like tailored clothes). In that case, the fidyah for that prohibited act is due, which is sacrificing a sheep in the Haram, or feeding six needy people, or fasting for three days.