I need help with my snake.

[SirPsycho]

Well I bought a boa constrictor red tail
About a week ago, I bought him a small cage he was living there for 5 days,
I tried to pick him up every day but he hates when I touch him he hissing and seem uncomfortable. I fed him at the 4th day. then I decided to get him a new big cage because he was a big snake, so because i couldn't touch or pick up my snake I decided to take the small cage and putting it inside the big one and let him get to it by himself.
So he was exploring his new cage then he climbed up to the small cage roof which was in the big one, he stayed there for two days.
Now I wanted him to drink some water or get warm so I wanted to get him off the roof of the small cage but I couldn't pick him up because he always seem to be aggressive so I lift the small cage roof up and then I accidentally droped the snake ;( he was fine tho and he is not in the roof now but what do I do with him? I can't touch him and especially now that he thinks that I am a threat for him after I dropped him.
Please help me, thanks