
1. Life has worth 2. You don’t know what comes after 3. The people in your life 4. Drugs and therapy are getting better by the day 5. Someone out there needs you- maybe you don’t think so and maybe not yet but they do 6. You want help- you wouldn’t be asking otherwise, which means there is part of you that wants to live
But your argument still relies on faith that there is no religion, if Christianity is true (I believe it is) then your reality is not limited to physics and what we understand. The world was spoken into existence, if He can do that, then believing in life after death of the physical body is not impossible either. So it just goes back to having faith in life after death or nothing. And both require faith so, no, you cannot be certain of what happens after you die. Nobody alive can be certain.
This is the same response that a island tribesman would have if you tried to explain to him about science and physics. The root of you not willing to accept that Christianity could be true is that fact that you think you know everything. You know very little in the grand scheme of things, how hard is it to accept that something that you don’t understand might be true.