You don’t understand the problem. The problem isn’t what you eat, how long you shower or which products you buy. The problem is we are converting fossile fuels that have been removed from the carbon cycle into CO2 and releasing it into the atmosphere where it’s going to be part of the carbon cycle again while increasing the total size of available carbon.

Now you may say "But if everyone does xy we release x% less carbon into the atmosphere!", which is naive at best. A lower demand for fossile fuels does:

a) not correlate with a reduced production of fossile fuels(as production quotas are set mainly with the relevant countries income needs in mind and many producers are afraid of lower future demand and are thus trying to sell their product now before it becomes worthless), lower prices might even mean higher production if the state needs a fixed amount of income.

b) reduces the price, which in turn increases the demand again. To put it plainly, if all the people go together and restrict their use of carbon products as much as possible we might slash the oil price to a fraction of what it is right now which in turn would make it extremely attractive for third world countries to use fossile fuels to meet their energy demands.

What’s the point if countries in the west use 10% less oil, the price goes down and people in Africa and Asia use 30% more oil because it’s more affordable now? The only thing that would truly help is a world wide oil and coal production quota that over time gets reduced to zero. As long as we keep burning oil and coal, at an increasing rate I might add, individual contributions are meaningless because we don’t truly affect the oil production, we affect the oil price, making it cheaper and everyone should understand that cheaper oil prices are not a good thing for the climate.