i used products containing glycolic acid before and i didn't use sunscreen it cleared all my acne but my skin got really sun damamged and now i stopped using this product and used vitamin c product it helped me making my skin better, however now my acne has come back, i want to start to use glycolic acid moistruizers again since it's really effective in removing my acne and now if i put spf 30 sunscreen on in the morning will it last me for a whole day???? since i go college and i come back at night. can anyone give me some information on how to use the sunscreen to prevent the burning effects of glycolic acid effectively?? without harming my skin anymore but keep on my skin clear???