Am l inadmissible to get a green card?

[Unforgivennn]

l had a mental disorder in the past, my disorder was Psychosis, and was about fear and phobia, Though l was institutionalized, after a short time l was rehabilitated and now l can bring any doctor's letter or any document that proves l am fine, except the documents that belong to past.

 

[FlyingRon]

Presuming you otherwise qualify, the standard is not that you have (or have had) a mental disorder but whether that disorder led to "associated harmful behavior."
Further, being OK now, means nothing. You need to show that if you had such behavior it is unlikely to occur.

You need to take your records to a good immigration attorney.