Ah stress, another popular dragon. Been there, done that, and it still comes up for all of us. :-)
I can tell you what I did personally that reduced my stress amazingly. i had high blood pressure since my late teens, and in a couple of months I made it literally go away. that's the power of relieving stress - i think most ailments can be cured if we find the reason "underneath" for them.
Here it is: we both took up regular meditation. The point is not to "meditate", whatever that means to whoever reads that word. The point is to calm the crazy mind which is usually freaking out like a neurotic wild animal on speed.
So you sit still in a comfortable place for 10 mins or more, close your eyes, and focus with all your will on nothing - truly on calming all the insane chatter in the brain and making it quiet inside.
Getting your mind to focus on nothing and push aside all your other problems and concerns (just say "i'll get to that later") is a very interesting exercise and will help you get centered and less stressed.
What helped me to relax and meditate regularly was
a CD program called Holosync, we still use it daily after 4 years. They have a lot of advanced levels, etc... but your focus is to get the free demo and see how it feels. then maybe get level one - keep it simple. I'm not going to go into the subliminal benefits of holosync and all that stuff, that's for another day; you just want something that helps you dive to a state of peace (alpha level) and stay there easily.
We go through a lot of personal growth stuff (actually starting a site on that topic in a few weeks - watch the strip of links at the top of our website for the link). What I like about Holosync is that it's SIMPLE. you don't have to "learn" anything. just find a comfy chair where you'll be left alone for 10 mins, get a CD player and earbuds (oh yeah, you must use headphones/earbuds for this) and hit "Play". You just listen to the soothing sounds (plus the submilimal stuff that helps take you down fast, that's key) and you let your mind get calm, that's it.
Get the Holosync demo CD and see how it works for you.
And something else to consider... be sure you're focusing not just on the sex, but on the lead-up... after all, it's not just about sex in bed. it's about playing and enjoying one another indoors, outdoors, in the bed, out of the bed, etc... back to the brain being the biggest sex organ.
Play games, tease one another, plan sexy romantic fun stuff you'll do together. maybe early in the week start planning that really hot date for Friday evening, so by the time it's there you're both looking forward to it.
And here's a fun one... The Fantasy BoxStart exploring each other's fantasies. seriously, short on time today but we have an idea called the "fantasy box". you each write a few pieces of paper, each with a secret fantasy, and put them all in the box. then on "hot date night" you pull out a random one from the box. nothing like letting loose some hot intimate sexual fantasies to bring you closer together and encourage some amazing sex. :-)
let us know how it goes!