CBD and CBG are two completely different cannabinoids. They also have a significantly different base taste. Sour Space Candy is a hemp strain where we use those terpenes as a flavor in our oil. It has nothing to do with actual sour, space or candy. Whereas Mint and the other flavors are essential oils.
CBD does not make you sleepy. Any 'sleepiness' is relative to being relaxed. CBG is the same. CBG has a tendency to help focus and energy. People claim it makes them sleepy but only because they were very stressed and now they are not stressed, allowing them to relax, and thus feel tired.
Being 'strong' enough is all relative. If you have a 700 mg bottle and a 3000 mg bottle, the difference is potency. You can still take the same amount of 'CBD' by simply taking additional doses of the 700 mg. In summary 1ml of 700 is the same as 1/4ml of 3000. 1/4ml of 700 mg is only 5 mg of CBD. 1/4ml of 3000 mg is 25mg of CBD.
If you are getting an upset stomach, it is because you are swallowing it. You shouldn't be. Place it under the tongue and let it absorb for 30-60 seconds. I personally them take whatever is left under there and coat the inside of my mouth spreading it with my tongue. At this point, I don't believe I have ever swallowed more than a typical amount of 'saliva' in my mouth. If MCT oil by nature upsets your system, we can use grape seed oil, avocado oil or hemp seed oil as well.