Liz, congrats on 7 pounds!
That might not seem like much but as I and you know, loosing any weight can be difficult....and I really like food.
Good for you!!!
What works for me is the treadmill. If you've never done that, start out slow and work your way up to a comfortable speed and incline. This will take time to get to a speed you are able to reach and maintain so be patient.
Pay attention to any pains in knees, joints etc. and if they are persistent, you might be pushing yourself too hard.
I'm not a real doctor but I do play one on TV.
Good luck to you!