I wouldn't. There's no regulation in this area, and you have zero idea what you're getting. The applies to a lot of supplements especially if there is no patent - did you see the news reports on GNC and Whole Foods for selling things which, when tested, had totally different amounts of vitamins or minerals, and sometimes none of the advertised ingredient at all.
As most athletes know, caffeine causes problems, including dehydration and, in some cases, heart rhythm problems. The dehydration is a big problem anyway, and it's made worse when people are suffering from sleep deprivation. Then there's the crash afterwards. The energy drinks are even worse - just way too much and impossible to control. Ask paramedics/EMTs how many people they are picking up who are overdoing those.
If you can't get going in the morning without a shot of caffeine, you're overtired and undernourished and possibly dehydrated. Everything slows down. You have to cut down screen time in the evening, have a dark/cool bedroom, and get more hours than you probably are. You know soda is bad for you but I think you need to go through the withdrawal and get it over with. You can expect a headache for a couple of weeks but push through it - that's the addiction part of this that makes you so dependent.
I work in food science with top people in the nutrition and epigenetics fields, and I only use products that are tested and whose ingredients are quarantined and pre-tested as well as tested after production. Most have patents (an accomplishment which most companies aren't willing to go through the testing/analysis, research, and expense to obtain) as well as the FDA Good Manufacturing Practices designation. Using real science and not cutting corners with cheap caffeine makes more sense for focus, increased blood flow to the brain, and stress reduction. That's the only way to go.