I've been where you are several times; trying to use logic to justify life and suffering. The problem, of course, is that life isn't logical.
I'm not here to try to convince you of any inherit meaning or purpose to life that will make you feel better, because frankly there isn't really anything I can say that will satisfy the doubt that is driving this obsessive cycle of yours. No matter what anyone says, you'll continue to experience thoughts like, "yeah, but what about this or that?"
The only thing I will challenge is this sentence: "I have severe ocd and my life is just suffering"
We often get caught up in absolutes (especially those of us with OCD). We tend to think that it's all or nothing, black or white, good or bad. I would challenge you to put this to the test. Is it really all "just" suffering? Or is that a massive oversimplification?
As humans, we evolved to have a natural negativity bias. It was always more beneficial for our survival to remember negative things than positive things. But in the modern world where we aren't fighting for our survival on a daily basis, this negativity bias is extremely unhelpful.
Psychological research has shown that while we very easily remember negative experiences, it takes roughly 10-20 seconds of "savoring" a pleasant experience to really encode it in our memory. So my advice to you is to try to catch any moment where you are experiencing something pleasant; no matter how small or insignificant it may seem, and take roughly 10 seconds to appreciate that moment. Notice what you sense in that moment (sight, smell, touch, etc, etc). Basically just try to be present and mindful.
Maybe it's taking a bite of your favorite food, walking down your favorite hiking path, feeling comforted by a family member or friend, the feeling of a warm shower, or just when you're feeling generally "at ease." When you become consciously aware that you're experiencing something pleasant, savor it, then let it go. Maybe this won't fix all your problems, but just see if you notice any changes at all by doing this. Maybe you will, maybe you won't.
Now as for these thoughts about the meaningless of it all, the approach that has helped me in the past (which basically aligns with the ERP standard of OCD treatment), is to essentially agree with them. Not in a defeated way, but in a, "yeah, so what?" kind of way.
If you have the thought, "life just sucks and death is really the only escape from it." Rather than trying to wrestle with that thought, see what happens if you say, "you know what? You're probably right! This is all pretty absurd, isn't it?"
This may seem like a ridiculous (and probably scary) thing to do, but what this does is expose the thoughts for what they are: just thoughts. For me, I eventually came to the realization that *my resistance to these existential thoughts was causing more suffering than the actual meaninglessness of life.* In other words, the thoughts are not the problem, and neither is the potential "meaninglessness" of everything (which of course is its own philosophical debate, and not *really* the focus here).
You can say "yes" to these thoughts about suffering and meaninglessness, AND still like the taste of pizza. You can like warm summer nights and cozy winter days. You can enjoy times with friends and family. But you can't enjoy those things if you're caught up trying to logically "prove" your thoughts right or wrong. If you find yourself stuck in a spiral, that's when you need to try something different. Call the bluff: "okay, yes this is pointless. What's your point?" If that makes you feel uneasy in the moment, then just notice that uneasiness. Allow yourself to feel it, because it's okay to feel uncomfortable. It will come and it will go, just like everything else in the universe.
Ok I'm just blabbering now. Hope something in there is a little helpful.
