Oh wow.. That sure is rough. You won't be around as much with your gf and puppy if you join the Marine Corps. Have any friends, family, etc who can hire you? Explore all your choices first. I can't really help ya there, as I don't know much about it. :(
I'm 21 now, in need of a job, and on the verge of joining the United States Marine Corps. My girlfriend and my puppy are the only two things that keep me going.
HG/SS coming out = almost getting me back into the Pokémon phase. Lurking this place and Serebii imagining what it would be like if TPP was still going strong to this very day, lol.