Will...sorry, I see you're Navy so go to the Navy WW Program Safe Harbor:
Link Removed
No discharge is not inevitable just because you have a combat injury, the med board will decide if they can fix you and/or reassign you. That is a administrative process and is slanted based on the pending drawdown, needs of the service and your personnel injuries and skill. A discharge may happen based on the drawdown and politics but you can always fight it, the issue is how much will that fight prevent you from healing.
...So is a discharge inevitable? That's the main reason I never reached out for help.
I understand the stigma of seeking treatment for these injuries as it was a big deal for Military Intel folks since they didn't realize that PTSD could not be investigated for their clearance, only crime or poor behavior but not a diagnosis. Otherwise it is discrimination. Look at it this way, how good was your chosen way to deal with it? Self medication is very common but far more destructive and harmful to your career. You see seeking treatment is a far better option, the best option, most of us agree the ONLY option.
A PTSD diagnosis cannot be used against you or it is discrimination but people, especially bureaucrats, service personnel staff can be complete, reckless ego-driven dicks, likely since most of them were never in combat. Regardless, none of this BS and speculation is worth your sanity and health.
Your mission now is to seek treatment and focus on yourself so you can move forward. The system will sort you out as it needs to based on who is involved and what the current requirements are, they'll play by the rules or slant them to serve their purposes.
Your best option is to get a Care Manager/Advocate from Safe Harbor to insert themselves into your case on your behalf to limit your stress with it. Once in, you'll be in Safe Harbor for life as a Navy Wounded Warrior. They are basically your short-cut to getting to key decision makers and personnel staff.
Stay safe, stay strong...