Yeah - let me get in to the 2:15's before you try manual
On a serious note, it will take some getting used to if you aren't used to manual gears but practice and stick with it. You might be slower to begin with but you will be faster once you're used to manual gears. As a general rule you want to do all your downshifts in the braking zone and not while turning. You want to change down pretty quick while braking but not too quick else you will lock your wheels, finding the balance comes with practice both at using manual gears and the specific car you're using. Finally, you don't always have to change gears - the advantage to manual is sometimes you can hold a gear so you don't change up right before a corner or use 2nd to get out of a hairpin rather than 1st to avoid some wheelspin etc.