Hi momofthree,
As luck would have it I am encountering the EXACT same situation as my dd also has reflux and I understand completely on the night feeds and wound up thing. We are having an ok time on Staydown formula but she cramps up and it requires a military operation to prepare so we are up about every 2 - 3 hours.
It's a challenge to relax under your circumstances and my general comment would be -- you have to learn to do it. There will be no miracle cure, but a series of trials and errors.
I would organise my approach to relaxing in several ways as just telling yourself to relax will never work and often makes it worse (I can't relax! I can't relax!).
Give yourself a good start before night time begins. Try to get some physical exercise in during the day. Try to eat dinner earlier so your tummy doesn't keep you awake and eat things that are smooth to digest. Unfortunately alcohol usually disrupts sleeping patterns so if you can, stay off it. Same with caffiene and pop. Instead (woo hoo!) drink warm milk (some kinds are actually night time milk which helps), or a bedtime tea. I put honey and cinnamon or almond milk in mine so I don't feel like a total grandmother.
Maybe take it one at a time. If you can, take some turns at getting up instead of both of you together. I am able to do this as my dd is on formula but if you are bf perhaps you can express and your dh can do a shift. When this happens, I use earplugs AND an eyeshade as I can't sleep if I hear them in the other room. But earplugs work wonders! Same for your dh when you get up.
When you are awake, keep the atmosphere relaxing classical music or something relaxing you enjoy. I have a little dvd player and some earphones and watch a short comedy show. An ipod or similar will help when baby is crying or playing and you need a diversion but she doesnt. Make sure you have some place that is a bit of a sanctuary for us it is our bedroom which we try to keep unchaotic and have clean linen and good pillows etc. that make being in bed enjoyable even if not asleep. For my friend she has a rocker and some relaxation tapes (these are easy to find on amazon). A warm bath works wonders to relax but sometimes doesn't help get you to sleep. You need to experiment.
When you are trying to sleep, just keep taking yourself through some simple body relaxation techniques (start at the toes, relax them, and work your way up till you get to your forehead etc. You will lose your train of thought and start thinking about other things and when you do that, just take yourself back to your body and start again). You could perhaps try some meditation (closing your eyes and walking yourself through something/place that makes you feel relaxed myself I do a country place at home in Canada or tell myself a story about a fairy I used to love as a little girl or I imagine doing activities with my dd in a year or so or I picture my dd when she is fast asleep which I still find very calming again I lose my train of thought as I start to worry about dd again, but just keep taking myself back).
When neither of you can sleep, try talking about things that you both enjoy -- planning a trip, etc. Preferably keep forward thinking (to a time when this is over for as we both know it doesn't last for ever). Or if you can, try massage (or sex). I know that's a tall order when things are chaotic at night, but it works if you can get past the first bit which is that it is the last thing either of you feels in the mood for. The worst is when you wind each other up.
Finally, just keep starting again. Don't give up trying to relax. Every time you lose it, just start again. Lean what doesn't work at all and what works a little and what works sometimes and what often works.