The Veterans and Reserves Mental Health Programme is a Ministry of Defence (MoD) specialist service that provides mental health assessments and treatment advice for veterans and reservists.
It works closely with the NHS and DMS to provide appropriate treatment.
You can usually only access this service if a GP refers you to it. Ask your GP about a referral if you feel your time serving in the armed forces has affected your mental health.
GOV.UK: Veterans and Reserves Mental Health Programme.
Further details of national support is available on the NHS website here.