There are several threads over the last few years on these questions. A Google search will probably yield better results; put “service academy forums” in your search string. That may work better than the SAF Search tool.
The other posts have been from midshipmen being involuntarily separated for a medical DQ for a medical condition or injury that prevents commissioning. As I recall, they do get some benefit for that condition from the VA. Your case is somewhat different as a voluntary separation. I don’t know how that impacts your status. There was a link posted to a primary source in one of those recent (last year or so) threads that addressed this.
Va.gov is going to be your primary source. Even though you have been in an AD status since I-Day, you are in a pre-comm program. There are times when being in an entry program such as USNA, OCS, etc., puts you in a different category when it comes to the VA. (Later edit, I think this will not be an issue, see link at bottom of post).
Your discharge - have you checked with Midshipman Personnel to see what it is likely to be in your case? Administrative discharges, in your case, can be either Honorable or General Under Honorable Conditions. Related to what I just noted above about the entry-level program, there is no doubt a policy and precedent as to what will be put on your DD-214.
Keep all paperwork you are given, particularly that DD-214! That is the critical document that records your time and status in uniform. Read all the fine print.
The VA defines veteran status very specifically. Benefits, if any, flow from that status.
Be sure you have full and detailed documentation in your military medical records on your leg injury and your full medical record. Make paper copies or get an electronic copy. Once you are separated, they are like unicorns. If you are eligible to apply for VA medical benefits, there has to be proof of the injury in your military records. The VA has to determine if there is a disability related to that injury through a medical disability evaluation at a VA medical facility. They then make a determination. The big first step, though, is you have to submit a disability application with supporting documents.
Out Gate 8, take a left, go past the fire station, and a block or so down on your right, there is a VA Community Center. They might be able to point you in the right direction for your research. There are certified VSO counselors out there who help veterans with VA applications. Quite often counties have one, and organizations such as the American Legion, VFW, DAV, etc., have them.
Your first question, though, is your eligibility to apply. That’s why I think a chat with someone at that VA Community Center might clarify things for you. At least there is no time limit. I just realized - you are probably at home. Look for a VA Community Center in your area. Or, see if your county or state has a VSO location. Or, go to the DAV website, they have mobile vans with VSOs that go to places like Walmart parking lots to meet with veterans. Or, your local AL or VFW chapter will likely have a VSO. Be prepared for some level of unfamiliarity with any claim to be AD or veteran based on your USNA time. The link I provided gives you standing. These folks are all volunteers deserving of appreciation. Of course, COVID-19 may impact their availability.
DOD military medicine and the VA are two separate and distinct organizations. No one at Brigade Medical will likely be able to advise you. Most of us who served knew zip about the VA until it was our time to get the DD-214.
I am reasonably sure you will have no educational benefits from the Fed VA. BUT - each state has its own veterans’ agency or department, and they all have different and sometimes looser definitions of “veteran” when it comes to benefits. Go to your home state (“state”.gov) website and do the research. One of our sponsor mids who separated was able to finish his degree at a home state university as a veteran under his state’s veterans program.
Good luck. I am sure this was a difficult decision to make, but the system is designed to let you do this without incurring OBLISERV. Voluntary attrition is predicted and expected. If you have realized you do not have the willingness to serve, then you will not be happy as a JO, and it’s best you shift course.
Other posters may pop up with that link I was talking about that addresses service academy mids and cadets with regard to VA medical benefits. Since you are voluntarily separating, and apparently not because of the leg injury, the burden is on you to do the research, see if you are eligible, apply, etc.
To get you started on your research, the link below documents the AD status of midshipmen at USNA, a good thing. There are hundreds of websites out there, but va.gov is your primary.