Be careful if you get a second dog, 2 dogs are not necessarily better than one. We tried that and our barking dog is worse!!
we do walk her before...and then play with her when we get home. We couldn't have her doing too much because of the stitches in her paw, but they came out yesterday. We're trying to find someone to come by to take her for a walk but we've been unsuccessful so far, but it really hasn't been long.
Your dog is barking because she is bored to tears. Either get another dog to play with her during the day, or reconcile yourself to a lot of walking before and after work. A tired dog is a good dog. Dogs need exercise so they're good and tired when the rest of their pack is away. If you can't do that yourself, can you maybe hire a walker to do it for you? Even a teenager who can come over before or after school would help.