Forgot to mention previous visa refusal :( Please help

[legalfalcon]

@legalfalcon GCMS Notes as Follow :
I have reviewed the application.
Ihave considered the following factors in my decision.
-The applicant does not have significant family ties outside Canada.
-PA has undeclared US refusal given intended to work in US without a WP.
-The purpose of the applicant's visit to Canada is not consistent with a temporary stay given the details provided in the application.
Weighing the factors in this application. I am not satisfied that the applicant will depart Canada at the end of the period authorized for their stay.
For the reasons above, I have refused this application.

*undeclared US refusal: I was randomly selected in the DV-2016 program (Diversity Visa Lottery) on the day of my interview at the US ambassy in SENEGAL the Visa Officer told me that i wasn't eligible for the program because i didnt have the Highscool Diploma (which was one of the required documents). As this happened in 2016 i sincerely forgot about that refusal.
But the Visa Officer deliberately accused me of having an intention to work in the US without a WP

I didn't receive PFL, and the previous application was in Aug-2024, i am now reapplying and i need Help more specifically on the Undeclared US VISA Refusal, I've drafted the New LOE and i've explained all the points they mentioned in the GCMS, but am partially afraid that the LOE became about 4 pages instead of 2 because i explained all the GCMS Notes + my Study Plan.

Any recommendation would greatly help me and others that maybe facing the same.

Consult a lawyer. You need professional assistance, and not general guidance from forum.