My dog has a lot of anxiety and I have used many different techniques to try to deal with it. When he is having more intensive anxiety, I make that we follow a specific routine with a longer walk before I leave for the day. I also changed him from a plastic crate to a wire one which made a lot of difference. I also increased how much work we do ex. heeling while walking and sitting at every intersection. This is more mentally challenging for him and provides a distraction from things that are bothering him. He now is very comfortable and doesn't show the same signs of anxiety that he was. I have spent a lot of time training him and working to desensitize him to specific things that trigger his anxiety. I have also used the calming pheromone collars which I thought made some difference but didn't fix it all.
For more situational anxiety, I alternate between using a DIY thundershirt http://k9ofmine.com/diy-thundershirt/ (primarily for thunderstorms and fireworks) and benadryl. There are multiple anxiety meds that you can talk to your vet about if you think the anxiety poses health risks for your dog.
Your dog sounds bored. More playtime, get another dog to play with, for anxiety leave a special item of clothing with pitbull, and talk to her/him! Calm and consistent.