When are we not ourselves?

[KUSA]

What if our material self is completely irrelevent?

Then we wouldn't need a body.

What if we really are biological support systems for our consciousness?

We are. However when the body dies, so does the consciousness.

Sometimes I feel like that, but I cannot accept it.

You sound like an Atheist.

I cannot accept how evolution could or would want or need this.
We are just animals, right? Walking meatbags who have learnt to help one another as a means of survival.

We are just rotting meat. Each day that goes by you get more rotten. You know that old people have a distinct smell of rot? Look it up. Old people all have that smell. You will have that smell one day if you don't blow your brains out when you are still somewhat fresh.