There is nothing wrong with you. You are simply having a normal reaction to the glamorization of war presented by Hollywood and the Pentagon.
Joining the military and selecting a combat arms MOS is not something be done on a whim. Success in combat and the infantry branch requires a committment not unlike that of a strict religious order. It's a tough lifestyle that is simultaneously boring and tense.
There are no half measures on the training field or the battlefield. To survive and win in combat you MUST be the best soldier you can be. Hence, it is not an "itch" that you can scratch.
If you find yourself wanting to explore the military option further then I suggest you avoid the traditional routes. Find your nearest VA hospital and volunteer there on weekends. You will see first-hand what combat and active duty can do to a man's mind and body.
Then go the American Legion local office and volunteer to put flags/ornaments on the gravestones at the local military cemetery. Look carefully at the names on each headstone, and note their ages.
That's reality. No second chances, no "reboot", no time outs.
Also, read "About Face" by Colonel David Hackworth.
Sacrificing your health, body, sanity, and even your life to protect the people who are important to you is and always will be a noble undertaking. Just make sure that's the REAL purpose of those who would recruit you and send you into the meat grinder.
In the meantime, you might want to sate your appetite for destruction in a more tame way:
1. Martial arts
2. Fencing
3. Paintball
4. Airsoft
5. World War 2 or Vietnam reenactment groups.
A more practical and useful path that would be of more benefit to yourself and your local community would be to (one or more of the following):
1. Achieve and maintain an excellent level of physical fitness.
2. Become a Red Cross volunteer and become certified in First Aid/CPR/AED
3. Obtain EMT certification.
4. Read "The Truth About Self-Protection" by Massad Ayoob.
5. Learn a martial art.
6. Learn how to use a handgun and a longgun.
7. Learn how to be a leader.
Whatever you decide to do, it must be your decision. The consequences, or benefits, may stay with you for a lifetime.