Controls are pretty hard on mobile, and there's so much enemies compared to pills that maybe drop once in a two minutes.
I can't beat the first 'babe' and it's very frustrating to be honest.
Sorry to hear you find it challenging. The pills will drop more frequently as you remove more clothing. By the end, there will be too many to collect them all.
I tried designing each babe with a unique play style. So for the first babe, you could try aiming on the far left such that the first few blocks you clear reveal her left boob. Then you should have access to regenerating your ammo by shooting her nipple and collecting the droplets.