Your denial will be in PADS and if you fail to report it on your PHQ, you will likely be denied again for failure to disclose.
The regulation 10CFR26 is your guidance. The minimum denial period for a first time FFd fail is 14 days per the NRC. The licensee can implement stricter standards, which may be why the other person was denied 3 years.
If you look at your initial denial letter, it may have guidance on any requirements (treatment) you need to complete prior to reapplying.
When you go back through the process, you will be required to have a substance abuse evaluation. The SAE will determine if your treatment is sufficient or need more. When you do your urine test, someone will observe the urine leaving your body. If you make it through the process, you will be required to be in a follow up testing program, which means you will have more frequent drug alcohol screenings over a specific time period.