Took me about an hour to pull it out. If the B2B is broke you will know it right away, it will be in pieces. Takes about the same to reinstall. Most of it is easy work.
Most of the work to pull the B2B would need to be done to get the trans out anyway, sounds like you are headed that way as it is.
You might try pulling the trans pan and looking for metal shards. I am not a trans mechanic, but seems to me to me you either have a valve body problem, or a trans pump that is failing. The torque convertor sometimes starts to break up and it takes out the pump. That is a common failure on these transmissions.