How/can I get out of a military contract (US NAVY)?

I recently signed a contract to ship out in october as an AD.. well I needed to move up my ship date so I ended up taking STG which my recruiter had told me has a top secret clearence and an automatic E4 after my A school and advancement would be easier as it is undermanned. shortly after accepting this job I researched it and found out that you still need to meet all the requirements including time minimum in rank. I have also begun to speak more with people in other branches and realized the Navy is not for me. I still want to serve my country but not as a Navy personel.. I would also prefer something a little more respectful then just not showing up...