TTC can be very stressful, especially if it feels there is an urgency to have it happen soon. Before I conceived the first time, it took almost three years of trying and I understand how frustrating, depressing, and confusing it all can be. It can also put a strain on the relationship. Back then I talked to my doctors about as to when to start seeing fertilty specialists, and I was told that after one year of timed intercourse and I am still not pregnant, then I should start having all the tests done (ovarian challenge test, sperm analysis, blockage of tubes, blood tests, the whole work-up). Now it depends on your age, if you are over 35 and closer to forty, the time trying on your own might be shorter. Costs vary by clinic/fertility center. Also, it depends on your insurance, as some of the tests procedures might be covered.
For me it was important to reduce the amount of "planned" intercourse, as it put a lot of stress on me (more so than on my husband). I really learned my cycle (when I ovulate and when not), so I did all of what is described in the book "Taking charge of your fertility" (charting, cm, etc.),plus OPKs. My OB also said to have intercourse on the day I got a positive on my OPK and the day after would be enough. Not more. This helped to lower the stress too for me. The OPK's then also worked in sync with my temp patterns, so I started to know when the right time was.
You might be doing all of this already, but as has been suggested, you might want to take a break from it for a while. Breaks from TTC helped me too and perhaps it might make it easier for your husband as well. (and I would try not stress so much about the two year PE window).
MC 3/2009 and 3/2011Henry
(1/1/2010-1/7/2010) - forever loved and missed; severe PE with Hellp; partial placental abruption, classical c-section at 25.6 weeksMatilda
(Nov. 2012, born at 35.4 weeks) - severe PE
Our pain has been put into words, placed into empty cradles, to remember that all our babies lived, that they mattered and always will. - Field of Cradles http://www.fieldofcradles.org/