Why was Hitler antisemitic...?

Was thinking about Hitler’s antisemitism and where it came from? I dismiss it was simply a convenient political choice because, after the First World War, Russian communist association with the Jews (re Trotsky) became a popular and hated, belief in right wing circles – because antisemitism was obviously a grounded belief with Hitler as otherwise, he wouldn’t have  continued to use critical military and other resources to further the holocaust when, after the battle of Stalingrad, they were so badly needed to win the war!

And yet his mother’s doctor – who Hitler admired through his efforts to save he beloved mother, was Jewish – while it was rumoured that Hitler himself was Jewish (it comes from maternal side) may be the reason that after Anschluss with Austria in 1938, he had all the family records meticulously destroyed.

So where did Hitler’s antisemitism come from?

I have a suggestion – that it originated in secondary school when Hitler had to share a class Ludwig Wittgenstein. Yes, the famous philosopher who was as well known for his impossible social manners as his impenetrable philosophy – which I reduce to,   ”… ïf it cannot be said – then it doesn’t exist”

He came from a very wealthy Jewish family in Vienna...