I, of course, understand that training personally with someone qualified would be ideal, so I'll start looking. Unfortunately, I live in Oklahoma, so there are A LOT of bogus martial arts teachers, tai chi included. There is a woman in my aikido class that teaches tai chi at our school on another night, so I may try that. Just have to find the time.
Have you asked your sensei about specifics for training the internal aspects of the art? Maybe they are just waiting for someone to step up and show interest.
At least I'm always amazed at how many questions I have that I don't bother even asking my sensei. I wonder why that is?