Can't? Or won't? Seriously, you're not unable to make yourself exercise, you choose not to. I'm going to let you in on a little secret: if you wait for motivation to get you moving, you'll never start. But if you do start, you'll stop shortly afterwards, because motivation comes by surprise and leaves as soon as the surprise has worn off.
Now, instead of waiting for motivation to come knocking and then hoping it'll stick around, figure out what you need to do, schedule in a time each day to do it, and then follow through.
Cardio doesn't need to be be hard enough to leave you winded. If getting winded makes you want to give up, then choose activities that won't leave you winded. Go for a walk. Walk at a purposeful pace 3 non-consecutive days per week. If you've got dogs, take them for a walk. If you're on your own, listen to some music while you're walking, or better yet, download some audio-books and listen to them. Start off with walking 20min, and increase that duration if you feel like it. 3 other non-consecutive days per week, do some circuit training: bodyweight squats, incline push ups, inverted rows, glute bridges and incline planks should be sufficient exercises to get you started. Do 10-20 reps of each (or 45-90 sec of planks) for 2-5 rounds of the circuit. This will be sufficient resistance training to keep you going for the first month or two. In that time, spend some time looking into your local gyms or equipment to get at home (personally, I'd recommend the gym membership over home equipment for someone starting out -- home equipment is of no value to someone who isn't using it, and a good home gym set-up isn't cheap; meanwhile most gyms cost $10-20/wk). All good gyms use olympic barbells and have squat racks and/or power racks. If you find a gym that doesn't have these things, you've found a substandard gym. All gyms are usable, but those with olympic barbells and squat racks are better.