i am afriad that any kind of sport requires dedication, be it fottball, strength training or cv exersize. you need to ask yourself, will you be happy with your body/mind if you give up?
answer=yes, it doesn't matter then
answer=no [i think this is you] grit your teeth, accept that you can't reap the benifits of the gym without going, get your head down and crack on.
sometimes i don't like training, but then i rememmber that i always feel [mind, not body] like **** and very dissapointed with myself if i don't go. [V]
one more thing is, IMO no matter how much you do, once a week ain't enough. i work and study full time [yes, both] and i still MAKE time for the gym or a home workout 3-5 times a week...
..you have to *want* to do it.
read my sig, exersize your will power and your muscles will follow.
hope that helps, its similar to what i realised when i was in your situation years ago. anyway, good luck matey