it appears some of my assumptions were not correct.  I assumed difficulty would be rising exponentially one way.  Your graphs posted indicate that difficulty & price are directly linked, and are not linear or exponential, but rising & falling.

If I assume price is related to difficulty, why does difficulty rise & fall?  The more I try to learn about BTC, the more complicated it is!   I'm not trying to understand all of it, just enough to decide my own involvement!  LOL