Post-op RP Sleep Anxiety: found cause

If any of you recall from a few weeks ago, I shared a post-RP surgical frustrating outcome: I have sleep anxiety...but no longer! I fell asleep just fine, but in the early morning hours just prior to awakening, I was conscious enough to feel a distress, and anxiety coupled to bad dreams, etc. I thought it was tied to my need to possibly urinate. When I was just awake enough, I decided: "OK...I'll don't 'need' to urinate, but I'll get out of bed to pee." I would return to bed and instantly note that my anxiety was gone. I related the anxiety and bad dreams to my apparent need to urinate.
Being a former Director of Clinical and Anatomical Pathology ("the Lab"), I went "all-in" analyzing this: "WHY" was this happening since my RP and never before? Other than the surgery itself, the only change was that I was taking a daily 5 mg low-dose of Cialis. My urologist said it is to help with circulation in my groin/penis, not for sexual function as is the usual case (I am still incapable - ED). I researched Cialis and found that some patients had sleep disruption to include anxiety. So...
I decided to do an experiment: Last night at dinner when I normally take it, I did NOT take my Cialis, and...BINGO...I had the best night of sleep that I've had since my RP.
I am a Type II Diabetic, and two years ago my physician had prescribed a medicine that combined two well known medicines into one pill. A very small percentage of those patients have horrific dreams when taking that combined-drug formula. I was one such patient. Odd thing is that I still take the two medicines, but as separate pills and without consequence (weird). So, I apparently have my psyche affected when I take certain meds, and yet again, my research discovered the rare, less common effect of Cialis that I experienced, and now eliminated from my routine. I see my urologist next week for my 6-month post-RP follow-up. I will have him change my Rx from Cialis to something else.
It is amazing...I awoke this morning without having gotten up in the early morning hours to urinate, and was actually saying to myself in my twilight awakening: "you slept well, you didn't have bad dreams, you're not anxious, you feel rested!"
Bottom line: if you have experienced anxiety, distress, a feeling kind of like having had one-too-many cups of caffeinated coffee, while sleeping or just waking up, and....you are taking Cialis...try a day or two without taking it, and see if you awaken feeling/knowing that you slept the best you have in months.