>I feel completely powerless and worthless.
Look, we are at war in an abstract way or in the normal way of it. In your
case, it's the former. The enemy (Microsoft, Netflix, Facebook, Monsanto and
all that kind of things you know) want the ones who fights them to feel like
that and they follow a simple war principle implemented in a complex
mechanism: "Let your enemy make the useless actions and block the relevant
ones".
You don't want to lose the war, but you can lose some battles. Take actions
that are really relevant against them and avoid the ones that cost much but
don't give that much. For example:
Relevants: Organize groups of serius study of the social problematics, join
and help this kind of groups, spread useful information to the population,
stop unjust laws, etc.
Irrelevant: All the actions that do not change significantly the society.
But before this, you have to be healthy in the social, mental and biological
aspects. So, get that first with all the excellent advices that the people
here have said.
And remember that you are not alone. You and the people like you (we) are
spread in the world acting and waiting for the right moment ;)