I know it's a comic, but I can suspend my disbelief up to a point.
I'm not really referring to the time paradox. I'm talking about Loki birthing himself whether as the mother or father. That's not probable unless somehow Loki possess the natural ability to physically clone himself using a specific sperm/egg plus the required specific genetic material of the male or female donor to produce himself twice over first as parent and later as the offspring, thus creating a loop. It's a lot easier to digest that Hela is his daughter and she's thousands of years older than him than Loki being his own mother.