From your strong reaction I would guess that your friend's reaction somehow ruined the model of the world you had, in a way that was connected with your life goals. Therefore for some time your life goals seemed unattainable and the whole life meaningless. But gradually you found a way to connect your life goals with the new model.

Seems to me that your conclusion #2 is too abstract ("far") for a shock that I think had personal ("near") aspects. You write impersonal abstractions -- "do people really desire progress? can actions actually accomplish things?" -- but I guess it felt more specific than this; something like: "does X really desire Y? can I actually accomplish Z?" for some specific values of X, Y, and Z. Because humans usually don't worry about abstract things; they worry about specific consequences for themselves. (If this guess is correct, would you like to be more specific here?)