Hi there, thanks for asking. You have explained the situation very well. It seems that your sleep has been affected by combination of several things. As you mentioned Modafinil can bring insomnia for some people. Prozac can cause restless leg syndrome and/or periodic leg movements (such people have very little REM sleep and the rest is mostly in the stages I and II as you mentioned) and also can change the architecture of your sleep. Some people who have GERD are susceptible to some degrees of sleep apnea especially if they are obese or hypertensive. Another factor which is affecting your sleep is polypharmacy (taking five medications just for your brain). They may help you to focus well during the day and also have enough energy, but they will bring for you a hyper-arousal state which makes shutting down of your system difficult at night. If you change your life style (for example to lose some extra pounds if your are overweight) and also reconnect some social networks (many people with PTSD become isolated because of avoidance from stimulating environment) you will be able to decrease the doses of your medications and also you will have better breathing and less reflux at night. I wish you the best health.