There is a section on the SF 86 (even if you have a valid clearance from being in the service, some/most government agencies make you apply for it again) that asks about your mental health history. That section of the form is very clear that any mental health counseling you received due to combat related trauma does not need to disclosed. I do not know if the form has been changed yet, but there was official guidance put out that counseling for military sexual trauma also does not have to be disclosed.
I think the only time it could be used against you is applying for LEO jobs, but that is unlikely.
2A rights are certainly a concern and I am sure that is going to come to a federal appellate court in the near future. Due process is due process, so I predict a victory for veterans and no SCOTUS case even though obama has appointed some clowns to the courts.