A time-traveling Jewish scientist goes back to 1891 to smother Hitler in his crib, only to return to the future to find out a different Fuhrer was able to win the war, making Europe a permanently enslaved continent and the U.S. its fascist ally. Now he has to return to the past, and kill himself before he can kill Hitler.

>>>After his plan to kill Hitler

He doesn't plan to kill Hitler. ? He DOES kill him. ?The dramatic question is: can he undo the assassination when it has unintended consequences; ?the "cure" turns out to be worse than the original "disease"?

>>>his original returns to the future, but the 1891 version of himself is arrested for being a Jewish killer of Aryan babies.

Say what? ?There are 2 versions of himself? ?Why? ?How does that happen? ?(And, yes, I'm quite familiar with "Looper".)

>>>After his plan to kill Hitler

He doesn't plan to kill Hitler. ? He DOES kill him. ?The dramatic question is: can he undo the assassination when it has unintended consequences; ?the "cure" turns out to be worse than the original "disease"?

>>>his original returns to the future, but the 1891 version of himself is arrested for being a Jewish killer of Aryan babies.

Say what? ?There are 2 versions of himself? ?Why? ?How does that happen? ?(And, yes, I'm quite familiar with "Looper".)

As Richiev wrote, simplify the premise to the bare components which have cause and effect relationship, cut all else.

I would only add a description that enables him to time travel:

After his plan to kill Hitler creates an even worse future, A desperate time traveler must go back in time to kill himself before he kills Hitler in the crib.