You might want to take a look at "Men are from Mars, Women are from Venus" if you haven't already. It offers good insight into how couples may think they are communicating and understanding each other, but may actually be totally missing each other's meaning and not fulfilling each other's needs. Wish I had read this one 2 years ago- although me & W are two women, I have discovered I often communicate more like a man (offering solutions instead of listening & validating). :-(
Also, the "5 Love Languages" is an eye-opening read as well. You may not have been saying "I love You" in a "language" your partner understands... what you learn from this one you apply AFTER you & W agree to work on M.
Me: 50; Wife: 48 Gay; civil union in NJ no kids M: 15 years, together 17 Bomb (OW) 2/09 (EA 3mos/PA 3mos) ILYBINILWY W out of house, w/OW, in separation talks, nothing filed