"I also collected early retirement that year"
was this omitted from your original tax return and reported the amended one? this would probably explain the large increase. if not read the following
we can not see your amended return. look at column B on the 1040X. that shows the change from your original return to the amended one.
if the only omission was the $1k of SE income line 1 that should increase by less than $1k (due to allowable deduction for 1/2 the SE tax). line 6 should increase by the tax on the increase on line 5. line 10 should increase by the SE tax around $150.
did you take credit for any taxes paid with the original return (line 16 column C ). Turbotax does not assume it was paid.
if this does not resolve the issue you'll need to look at each line and determine why it changed
