Yes, I agree it seems scary, but all it really means is that morality is not universal but specific to humans. You could say everything is inherently morally permissible in the sense that there is no higher power which will punish you for your actions, so essentially there is nothing preventing you from committing them. In short, the universe doesn't give a shit what you do.

Still, your actions do have consequences, and you are inevitably forced to live with them (pretty much Sartre's viewpoint). Because of this, doing things you think are wrong is often bad for you, because it causes you emotional pain in the form of guilt and regret, and also usually carries along negative social repercussions which outweigh the value of the immoral act in the first place. You could say that people are naturally compelled to act in certain ways out of completely selfish reasons. In this sense, I prefer to look at morality more as a "deal" between the members of a society to act in a certain mutually beneficial way (which is fueled by our instincts, a product of evolution), than something universal and objective.

The reason I doubt in our current understanding of consciousness is because I find its distinction between what is conscious and what isn't quite arbitrary and problematic. At which point does an embryo become conscious, and how can something conscious be created from something unconscious? The simplest explanation I can imagine is that consciousness is present everywhere and cannot be created nor destroyed. This view (called panpsychism) is absolutely ancient, but seems to be gaining some recognition again, even among neuroscientists.

As you mentioned, "cogito, ergo sum" might be the only real objective truth that philosophy has uncovered so far. I am an optimist in that I believe surely more than one such truth must exist. If it was only discovered 400 years ago, surely there is more to be found. Maybe it is possible to collect some of these small fragments and build some larger philosophical theory from them, one that will be grounded in fact and built up using logic. I guess only time will tell.

And yes, of course some abstraction is beneficial in order to make sense of the world, even if it isn't completely correct or objective.