No, secular philosophy doesn’t provide any basis for assuming that certain actions are good or bad - it looks at the outcome of those actions and determines their positive or negative character accordingly. You seem to have bought into the notion that the absence of religious faith = the absence of any possibility for morality, but I’m afraid the evidence demonstrates otherwise. Humans are moral animals through necessity, not through the imposition of supernatural purposes and directives. We’re imperfectly moral because we absorb information from the world we inhabit - morality, or the lack of it, is a learned set of behaviours.
You are already making moral assumptions here. To judge the “positive or negative character” of actions means that you have something to judge them by. Some goal or foundation. What are you judging them by? What makes an action positive or negative? How do you determine that? You have yet to provide a coherent system of morality.
Who are you trying to make a difference to? The universe doesn’t care. It probably isn’t capable of caring, but even if it could, we’re too small to matter to something so great. But why does any form of universal significance matter to the likes of us anyway? We’re hardly in a position to know about it. I think you’ll find that your own, insignificant life matters plenty to the people who know you and care about you. Do you take medicine when you’re sick? Do you take pleasure in particular activities or in the company of particular people? Do you attempt to avoid being injured or killed? If so, then it’s obvious that your life is worth something to you. It’s only the kind of arrogance stemming from an underlying belief that we ::should:: have some universal significance that assumes this isn’t enough.
Of course I care for my own life. It is animal instinct, fear of death. But instinct is never defined as morality. There are many things I can do, driven by instinct, which most sould disapprove of. Neither does it matter what those around me think, it does not matter if they care about me. Their passing lives will be over in short order and they will no longer care for me, or anything else.