If you think donating to the cause or supporting and "spreading awareness" about climate change on social media helps anything, then yes, your "actions" mean nothing. That's precisely because, they're not "actions". If you actually want to help the environment, posting on social media about how evil oil companies are won't solve the issue.

Go plant a tree. Make biochar. Sequester your own carbon by burning plant material and putting it in the soil where it's stored there for THOUSANDS of years.

So fundamentally, no. Your actions are not too small. Everyone can DO something, but the ones who claim to be the biggest advocates (liberals mostly) would rather just post on social media how much they CARE about the environment and attempt to force the government to flush BILLIONS of tax dollars down the toilet towards a problem that doesn't even really exist (let alone be solved by money). That accomplishes nothing.

Regardless, after the GDP of a country reaches a certain point, the population begins to care about thier immediate surroundings from an environmental perspective (as we can see now with practically all developed nations in the world). The problem will solve itself (assuming it's even a problem to begin with, which it really isn't).