Does "I am in good state/condition" mean I am physically great? If so, what is expression about...?
Does "I am in good state/condition" mean I am physically great? If so, what is expression about "I feel great emotionally"?

Question

Answer

Hi Ethan,
You can say "I am in a good mood".

Answer

There are many synonyms you could use to indicate that you feel great emotionally such as:

Happy
Content
Cheerful
Joyful
Jolly
Carefree
Untroubled
In good spirits
In a good mood
Thrilled

To name a few.

Answer

"I am in a good state" could mean financially, emotionally, work-wise, etc. It is more than a good mood. 
"I am in good condition" usually means physical health, and fitness. 
"I feel great emotionally" means they are happy, and content, and happy with their achievements/success, their relationships, etc.