Missy, stick with the sprinting. Do HIIT (sprinting with active rest inbetween) 2x a week, on non-lifting days. Example would be lifting MWF, and HIIT on Tues and Thurs. Start with a 4:1 rest to work ratio, resting being active rest. Start with 6 sets and work the ratio down to eventually get 1:1 work to rest ratio. So, for example, starting off week one.
Warm up 1st for 5 min (jogging)
20sec sprint
80sec jog/walk
repeat 5 more times.
You should feel somewhat nauseous, if you are then your doing it right. Do this in the morning before eating then eat a high protein meal, low in carbs to continue fat burning, be sure to include EFA's as well. Cut out all other aerobics and stick with that twice a week and lifting hard. Make sure you use "clean" carbs with your carb cycling diet, sweet potato's, yams, brown rice, oatmeal, etc. Don't keep burning muscle with the long aerobic sessions, especially with low carbs. It leads to high cortisol levels and is counterproductive to your goals. If your diet is right you should see results fast.