I highly recommend you give Blackshirts and Reds: Rational Fascism and the Overthrow of Communism and On Authority a read. At least On Authority, as it’s a very short piece, but the two combined should give you a basic understanding of the historical and theoretical basis of why marxists defend the use of authority. I can understand where you are coming from, I was more than a little skeptical of authoritarianism when I was younger and still identified as an anarchist, but I think if you take the time to honestly engage with our position then you will at least understand why our stance is what it is, and how we are diametrically opposed to fascism, even if you don’t agree with us.