you might wanna turn of the godmode(invincibility mode)
by turning the invincibility mode your character wont activate invincibility framies making the enemy hit you(touch) 10-20 times in a single hit dealing stacking knockback, turn it of and see if the knockback is still insane,
this happened to me a lot of times where i turn on invincibility mode to build my structures the and random slime hit me and giving me knockback at insane levels,
in normal terraria knockback stacks up to 3 times only but in overhaul in order for you to be knock back multiple times midair the knockback limit might be removed causing invincibility modes to stack up all knockback per tick while you are hit by a mob, (note 1 second is = 60 Ticks) touching a mod with invincibility ON will give you contact time of like 0.25-0,5 seconds and because invincibility frames wont turn on since your not damaged the knock back is stacked per tick tahst why you are having that problem
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also i dont know why but if your satisfied with thorium im fine with that but if you havnt tried calamity mod and Fargo souls mod, then you still have not seen modded terraria at its fullest,(note when you have fargo you might wanna toggle off all effects 1st before you equip fargo items) unless you want your PC to bleed