The Palbociclib Blues, Part Two

I've been in a clinical trial--Penelope B--for five cycles of what is presumed to be Palbociclib, the Pfizer drug marketed under the name Ibrance, and which is now used to extended the lives of women with metastatic breast cancer. Which I'm lucky not to be enduring. Last April, after sixteen chemos, two operations, and twenty-eight cycles of radiation, I got to keep my breast, minus eleven lymph nodes, and was declared cancer-free. I take a nightly tablet of Letrozol (2.5 mg), which is supposed to prevent a recurrence, and side effects include feeling old--I call Letrozol my miracle aging pill, and counteract the stiff hands with one of those rubber porcupine balls that I squeeze any chance I get. I take ballet and tap when I feel well, which is not lately.
Since I my tumor was small (Stage 1b) but aggressive (Grade 3) I was eager to take part in a clinical trial designed to further reduce any chance of recurrence.
During the last five weeks, I've been experiencing side effects. Two rounds of antiobiotics (Twenty tablets of  1000 mg of Amoxicillin-Trihydrat followed by ten days of Cefuroxim 500 mg twice a day) were not quite enough to get rid of the bronchitis against which I could not defend myself, my low white cell count, a common side effect, remaining insufficient to jump start my immune system's normal efficiency. As I type, I'm still snuffling with my endlessly stuffed nose, popping a Sinupret three times a day, and coughing.
So would it be worth my while to continue on this clinical trial? According to Dr. Second Opinion (but I did consult him before the bronchitis, when my only real complaint was the unusual fatigue) "Yes, yes, yes!" He whipped out charts and graphs, none of which I understood, but I banked on his enthusiasm for the figures, which clearly meant something.
 I've never needed a second round of antibiotics for any throat or lung infection, except for the time I had pneumonia more than eight years ago, when my kids were very young and I never got enough sleep, and ended up in the hospital.
So I asked, and am asking anyone who knows, the following questions, since the leaders of the study I am in don't really have definite answers, and perhaps no one does:
 (1) With the 2,5 mg. of Letrozol daily that I now take, what is your best estimate of a cancer recurrence without the Palbociclib? I know that some women take a higher dose of Letrozol. What difference would that make?
(2) What are the long-term consequences--in terms of exposure to viruses, bacteria, cancer--of the low white cell count that I now have?And how would anyone really know the answer?
(3) Can you say for sure that this medication benefits me, personally? Is it possible it only benefits the study?
By the way, my blood was tested, as usual, at the hospital, now that I just have a cold instead of bronchitis, and was pronounced fine. In fact, good! I could start taking the Palbociclib again right away!
Before, I felt fine but my blood looked just awful.
Is it possible there's no test to measure correctly the effect of Palbociclib on my blood? Theoretically, there may be no medical reason for me to feel lousy when my blood looks dandy. And dandy is how it looks, folks. But I feel anything but.
When I Google patient information, I get what everyone already knows. When I Google medical studies, I get, for example, this:  https://www.iqwig.de/download/A16-74_Palbociclib_Extract-of-dossier-assessment_V1-0.pdf but I feel inadequate to the task of interpreting the data. I don't understand the charts and I don't understand the medical lingo. I did ask my doctor, and she probably would not want to be quoted, so I will just say that my impression of what she said, strictly my very own interpretation, legally distinct from whatever may actually have emerged from her mouth, is that the German government needs to find ways to save money, because this extremely expensive drug, which I am getting for free, costs too much, so if one study says the tumors get smaller but the life expectancy remains the same, then that's a way of broadcasting the conclusion that too much money is being spent (notice how I deliberately used the passive voice there?) The criteria of good care is increased life expectancy. And one truth is still that it's really hard to tell what treatment or what drug did the increasing. 
If I had metastatic breast cancer, I'd down this drug with no complaints. What's a month of bronchitis when you get to live?

But I don't. I want to live the way I like to live.  So tell me, doctors, prophets, women with the same experience, anybody who knows more than I do (I really hope some brilliant cancer researcher is reading this): SHOULD I STAY ON THIS CLINICAL TRIAL or SHOULD I GO?