long term capital gain calculation and Net investment income tax 3.8%

Hi,

The long term calculation formula on nerd wallet:

 

0% for $0-$40,400, 15% for $40,401-$445,850, 20% >$445,851

 

1. I this the formula turbo tax uses for a long term capital gain?

 

2. Is the Net Investment Income Tax @3.8% an additional tax added to the long term capital gain?

 

I feel like I am being taxed twice on the same long term capital gain? Thanks! David.