It appears that the Pre-workout will have 230mg (460mg for full scoop, it's kind of split into multiple ingredients on the site) caffeine, a cup of regular coffee on average will have about 100mg (this can vary widely), then a single serving of Amino Energy has 100mg (two scoops, although there is 160mg of stuff in it's "Energy Blend").
So we can say more of less that you'd be getting around 430mg of caffeine from those sources.
The max recommended safe amount of caffeine per day is about 400mg, give or take depending on your sensitivity, age, and weight.
Is it okay to take during and after your workout? Well that's a lot to take 3 different sources of energy just for one workout in a 2hr period and then more throughout the day.
Is Amino Energy a fad? Not any more so then any other pre-workout, I like that it has fairly simple ingredients (mainly green tea extract and aminos). I've tried it, it tastes good but won't do anything more then coffee or tea.
Will Amino Energy help you get through a workout at a strong pace? That's more mental then anything, especially after 30min you feel you need more pre-workout.
If you are thinking the caffeine will help lose weight, it has been shown to temporarily slightly increase metabolic rates but your diet will determine your weight loss not extra caffeine.
Now the obvious question is why do you feel you need more supplements to make it through a workout and the rest of the day? Are you taking too many supplements? Are you getting enough/quality sleep? Are you over training? Are you properly hydrated? Is your diet healthy for you?
There's an infinite number of reasons to be tired so potentially look into solutions for that before "fixing" it with more caffeine. Of course that's easier said then done as I also take a pre-workout and drink coffee/tea during the day.
Wait you only feel a "bit tired during the day", I think that's just life.
