I don't know how much the elliptical is going to help you. I find that machine to be exhausting but overall never found any benefit or signs of strength or other improvement.
I started climbing the stairs in my 8-story building several time a day. That's helped my endurance quite a bit and given me more energy.
I think you really need something that (a) increases muscle and (b) gets your blood pumping
What do you like to do? I love power yoga, so go to classes twice/week. I also love barre, but got really bored with it so that's on hold and I use my old Kathy Smith step videos on occasion instead. I have weights up to 15 lbs and sometimes just use my step for a while while holding weights -- basically until I feel like failure is imminent
