My physical condition is so bad. My physical condition is so bad.

This is correct but it feels stiff. It feels like something a doctor or lawyer would say. Instead, I would say something like "I don't feel well" or describe what I'm feeling like "I'm achy" or "I have a bad headache".

My physical condition is so bad. My physical condition is so bad.

You could say "I feel physically unwell", this is still pretty formal but it's started to creep up in casual conversations with a touch of sarcasm/jest at how formal it is. I would say "I don't feel good"

My physical condition is so bad that I can't write anything to text. My physical condition is so bad that I can't write anything to text.

I can't write anything to text. I can't write anything.

I can't write anything to text. I can't write anything.

I would say "It is hard for me to write" because you are writing :)

I can't write anything to text.

gGood night. Good night.