Extending Dash-Trash's excellent suggestion, why not put the IREX on hold and start doing some training (impractical though if you're on a mission to get your rating in 2 weeks or whatever)?
You might find that actually having some sim time and/or navs under the belt helps you better understand the point of the concepts and rules that you're struggling with.
You don't HAVE to have an IREX to start the training..............
UTR.