Polygamy is a crime

Polygamy is a crime https://www.josephsmithpapers.org/paper-summary/doctrine-and-covenants-1835/259 Once again, this is scripture, supposedly from God, and then a few year later he's now ok with Polygamy? Why is god being confusing? Why is he constantly changing his mind? I thought he was the same always.

There are lots of things like this in the Mormon church where doctrine has changed and it seems like the church is led by the whims of whoever is in charge instead of a god. The other crazy thing about this is that in the first paragraph under the heading "The beginnings of Plural Marriage in the Church" in the gospel topics essay plural marriage in Kirtland and Nauvoo it says Joseph Smith got the revelation for polygamy in 1831. If that's the case then why was D&C 101 canonized in the 1835 version of the D&C? How is that not confusing? If God told Joseph in 1831 that polygamy was a law he needed to live then why did JS receive 101 as a revelation in 1835 and if it wasn't a revelation then why wasn't god "preparing a way for his children to keep his commandments" instead of causing confusion by allowing contradicting revelations and scriptures to exist at the same time? 

The more I learn about Polygamy the more certain I am that JS was a conman and not a prophet, billions of moral, good people have lived on this planet, people who would never take advantage of someone else, people who would be loyal to their spouse and never manipulate other people into relationships with them. Joseph hid polygamy from Emma until he had already married 10+ women, Emma was not the first woman sealed to Joseph, he even married a few people a second time so Emma could be present without admitting he was already married, he told some women their eternal salvation and that of their family was dependent on them marrying him. God had his pick of people on the planet to prepare as a prophet, Joseph was a horrible choice. I can't believe in the Mormon god that calls prophets, he keeps making such poor choices.