I don't care. Worrying about such long timescales induces a sort of paralysis. The solution to uncertainty about truly fundamental questions of existence is to work on fundamental math and physics, to figure out where matter comes from, whether other dimensions exist and are accessible etc. If you just feel discouraged by the pointlessness of existence, that's just a sort of vertigo or cognitive overload. It's better to pick something you like and scurry around exploring it rather than being stuck in intellectual catatonia. The best cure for this is to engage in something you find physically enjoyable; rebooting your sense of physical autonomy helps to shake off the cognitive paralysis. Go for a walk, jump around to loud music, eat some of your favorite food, or amuse yourself with comical imagery so as to alter your mood. The seeming futility of existence doesn't matter because it's on too large of a scale for you to experience or impact; the feeling that it overrides all other considerations is just a feeling.
Comments like this are strange since anyone with eyes can see that the break down of the systems we rely on is not some far off future event, it's happening right now and will likely escalate fairly rapidly in the next few decades.
It's not surprising that people feel stress from this and "walking it off" is not all that effective of a treatment.
I'm responding purely to the cosmic timescale brought up in the grandparent comment. I'm saying it's pointless to obsess over cosmic entropy because it inhibits one from doing anything about current problems. While current problems are stressful, reacting to that by fretting over the ultimate pointlessness or unsustainability of existence over the lifetime of the stars/universe is an unhealthy response to stress. Self-care and activity are more effective and productive, even if those long-term uncertainties remain unresolved.
