This is the classic case of preparing thoroughly at home, rather like memorising a sales script. Then the moment arrives: "Hello, how are you today?" And you have nothing.
Why you prepare ten things and use one
You prepared three answers in the order one, two, three. But nobody asks in that order. They ask you the second one, then ask the person next to you the first one, and then that person turns to you and says how about you?
And the script collapses.
Three is harder than two
A conversation among three people is always harder than a conversation between two, considerably harder. Joining a group of three feels uncomfortable, because you do not know when to speak or how to enter.
But that too is a skill. You have to track who is saying what, and know when to hand it on with a how about you?
Everyone in the group shares responsibility for bringing the others in. That coordination is part of communicating, not a side issue.
The takeaway
Learning a language is not only learning vocabulary and grammar. More than that, it is learning how to communicate with people. Communication is a skill, and skills are built in real situations, not by sitting at home drafting answers in advance.