Daily Caffeine intake

Have any of you really tracked how much caffeine you consume in a day in order to keep functioning. I need a minimum of 500mg. How about you?

I take about 2 caffeine pills a day. One in the morning and one in the afternoon. Plus, i down at least 2 diet sodas or two bing energy drinks.

Any advice on how to wean off. I have three little ones under 3 yrs old (1year old twin girls and a 3 yr old) so I need energy somehow.