I will use it for my mental and accomplishment?

Hi.

While writing about stress, one of my friends wrote,
"I will use stress appropriately for my mental and accomplishment."

Upon seeing it, there is something strange in it, I thought.

I guess what he meant by that is,
"I will use stress in a positive way so that it can help me achieve
mental growth and gain bigger achievements."

Do you, native speakers, also use 'mental' as a noun?

Urban dictionary defines it as

-the way you think, act or feel about towards things.

A : Man, he doesn't give a sh*t about anything.
B : Yeah, I wish I had his mental.

I would've told my friend that 'my mental' is awkward
as 'mental' is an adjective if I hadn't seen the definition
Urban dictionary showed me.

According to the Urban dictionary's explanation,
I guess what my friend wrote also could be correct?

How do you like my friend's sentence?
It still does need some correction, doesn't it?

Please share your thoughts.
Thank you.