Sorry, I’m in my work right now so I cannot type in Chinese.
I think it’s because the weather of US is dry, but you did not moisture your skin enough.
To me, the one "Olay-Complete Defense spf 30 for sensitive skin" is quiet safe. It never breaks me out.(usd $14) (But I got a dry skin, so I still have to apply moisturizer underneath, in summer sometimes I can put it alone )
A better choice for you is “Eucerin” for sensitive skin spf 30, (To me, it’s too try to put on, so I use it in my neck), it’s
“Oil-free, non-comedogenic (won`t clog pores)"
“Non-irritating and clinically proven safe for
sensitive skin”
You can visit http://www.drugstore.com/search/search.asp?searchType=1&srchTree=1&search=sunblock&ss=name&ipp=20&x=13&y=2&sc=66390&spc=40454&trx=SEARCH-REFINE-0-CAT-LINK
Actually , I think Neutrogena, coppertone, they both have oil free and non-comedogenic sun protect products.