I can relate, but cannot pretend to have answer. For years, at different times, and for no readily apparent reason there seemed to be an extra person in our bed. Uninvited, and unwanted, and only known to me. Many times it hampered the experience completely, and other times, well it just seemed to go poof and the extra person was gone. I know I was really trying to focus on my partner at the time it went poof, and not so much on my experience. I was more interested in giving than receiving. I think that might have rattled the ghost a bit. But as you mentioned, it does have an impact wether only partially successful or not. So I went to my Dr. and asked for her assistance. I've tried the Viagra with mixed to good results. Am now trying the new low dose Cialis daily dose. So far so good. My experience may not reflect yours though as I may be at a different stage. I'm still fairly new here, and only recently disclosed to my spouse, so that I think would have an impact.
I wish you well, and all the best in getting back a "fulfilling" experience with the person you love.
My name is Jim
WoR Mysthaven 2008, Level 2 WoR Alta 2009, Kirkridge 2010, 2011, Oprah 200 men