Pre pharm at LIU Brooklyn

Hello,
I will be starting the LIU brooklyn pre-pharm program in the spring of 2016. I was supposed to start in the fall of 2015, but due to circumstances it wasn’t possible. My main concern is that my advisor suggests i take 19 credits this semester with following classes:

Bio 1 (4)
Chem 1 (4)
His 1 (3)
Calc 1 (4)
Cos 50 (3)
Seminar (1)

I have never taken this many credits before, although i have done my A levels in biology,chemistry and physics and had a 3.85 gpa, i am nervous. They were offering me credit for these classes but i refused because its been a while since i studied them. He suggests also taking bio and chem classes over the 6 week summer. I dont want to do bad in these classes. What do you guys think? Should I take all these classes and finish on time (2 years) in order to apply to the Pharm program at LIU timely or take my time and apply after 3 years? Please help me out. Also, do the chances of being accepted to the LIU post pharm program lessen if one doesn’t complete the pre-requisites in 2 years?

Thank you.