Obedience will certainly help, *especially* considering that you are having other issues with Roscoe.
Not only will the classes themselves help but all reputable trainers will also take the time to listen to what problems you have & work with you individually on them.

If I remember correctly you said you just got him a 2-3 months ago? If so did you get him form a shelter or rescue organization? If so they too will (or at least should) help with training and possibly offer free training. I'd contact them too to see what they have to say.