I know where you are coming from.
Been there
Done that
Hated it
Try working out before you go to work, that way you will be full of energy (hopefully) after your workout, take your shower (that way, you'll only have to shower once a day), and go to work.
also you had mentioned you need to do more than just cardio. Try adding some wrist/ankle weights and hand weights. You can do upper body toning while on the tred and the legs will build lean muscle with the added ankle weights.
There, you have just killed two birds with one stone.