SaltyDog, Brenee Brown is AMAZING, and a great choice if Tom wants to break out of his comfort zone. Tom, the whole topic is how to be vulnerable and she has a chapter addressing common objections.
My W is a huge fan and got me to read some. I will say it was helpful and probably at least slowed her down a bit when she saw me being more vulnerable. However, it isn't easy toeing that line because it is tempting to go from vulnerable to needy or to close back up because it is uncomfortable. It's also a bit difficult at times with DBing because the two seem to be at odds in certain situations. But as far as helping yourself GAL, she is well worth checking out.