I hope you have been seeing a doctor about the anxiety attacks, since some medical problems can cause panic attacks, like hyperthyroidism. There are also some good medications available to help control them, but I imagine you've already discovered that. However, there still could be another medical condition causing the numbness. How are you treating the anxiety?
If you have good insurance or can afford it, a reputable physical therapist may be able to help you correct certain thing so you can develop your body more evenly.
You may also want to see a neurologist, chiropractor, and/or do acupuncture, like kandsk suggests. If there is something else wrong with your body, you could hurt yourself more by trying to correct it on your own.
I started having panic attacks when I was working at a very high stress job. The anxiety got much better over time but then kicked me in the ass about a year ago when I got laid off and lost my medical insurance. I also had some separate health problems and when I got insurance again I was able to put myself back together. I had a headache, pretty much non-stop, for over a year and had a lot of neck and shoulder pain. After many doctors visits and urgent care visits, I was referred to a spine specialist and neurologist and was diagnosed with myofascial pain disorder. I am now seeing a physical therapist and working out every day. I feel like I've gotten my life back. I used to hate doctors and had no faith in them, but I have a very different opinion of them now. The physical therapy has done more for me than any doctor or pill could.
So....hang in there and take good care of your mind and body. Do whatever it takes to get well and good luck.
To answer your question, dumbbells and resistance bands can be a big help; you can isolate the muscles. I'd stay away from barbells for now.