I actually wanted to wear makeup, but my skin is so sensitive so I ended up not wearing makeup often.

(I was a little confused. I think your intention is:

"I actually want to wear makeup more, but my skin very sensitive, so I don't wear makeup often.")

And I wasn't going to wear makeup to work, but since my boss told me to wear makeup, so I have started to wear makeup to work.

I used to only apply the only sunscreen. But one day, a friend said that I should try a new BB cream from B company.

So I did and I thought it fitted me well.

(It fit me well = 마음에 들어요?

Saying "it fit/suits me well" only works with certain things. I think you should say "and I liked how it looked on me" here)

So now I've started wearing makeup much more often.

Comment: Nice!! Your writing is awesome. Keep improving :)