Question about past forms and military

Hey so I denied my acceptance to OCS officially (Navy)

I did this because I was told to omit some drug use on my SF86 which I know is wrong. But

If in 2 years I want to go through a different branch, do I have to tell them I omitted anything or that I got accepted before ? The drug use would not be in scope of the investigation in 2 years.
I am going to wait 2-3 years. Form asks for last drug use in 7 years. The drug use I ommited on the original Navy OCS form is no longer applicable to the new form.

What should I do? Do I just give up on this?