This will probably be a very fierce attack on your life. Remember, the devil cannot hurt us. His attacks are basically limited to deceiving us. He wants to deceive us into sinning or into doubting the word of God. These are the two areas or strategies of demonic attacks.
The snake was black and huge and very aggressive. A black snake: A demonic deception with the purpose of deceiving people through intellectual reasoning. This intellectual reasoning influences people to accept failure and/or defeat which results in people becoming depressed. It causes unbelief in the lives of people. Evil forces always want us to give up hope and to sink in a hole of depression and to doubt in God’s word and promises. A black snake, therefore, symbolizes lies of unbelief to accept failure, defeat, and poverty.
The fact that it was huge and very aggressive, speaks of this attack is serious. So serious that you will need help. So, accept the fact that you will need help when dealing with this temptation.
The fact that somebody came to rescue you speak of God making provision in this regard. There will be a God-sent person or angel who will help you. The white robe speaks of a person who has the authority and who is holy and just and able to deal with this attack.
The floating speaks of God himself actively involved. It speaks of supernatural assistance. He will help you to deal with this attack (temptation) and no harm will come your way.
The fact that this happened at your uncle’s house and the fact that your cousins left you alone are both a concern. They may be involved and they will probably betray or at least abandon you.