I don't know how much you play each deay, but to be able to just grab the F cord like you can the G is about a 3 month task. Play G then F then C then F then G then F the C then so so so forh. That combination will help build strenth and keep the cramps away. Like anything else, start slow, don't even look for speed for a couple of days. When you no longer have to watch your fingers to make the cords, start trying to speed things up slowly.

Good Luck