Hi- I can't say long term (we have been trying for 6 months and had one miscarriage) but yes we are strained and I definitely think the pressure adds to it. I will be 39 in 2 months and DH is 44. We want one more baby, so badly. We've had no problems in the past, so I'm not sure what the cause is now. Possibly age...I also still have a 2 year old that sleeps with us a lot and just recently weaned him. Maybe it is God's way (or whatever higher being) to space the children apart since DS still needs me so much.
I feel your pain. It is so hard to say "okay honey, time to BD!" When you are arguing or things have been tense.
I hope you get a BFP soon :-)