Which protein shake to choose?

Protein shakes aren't necessary unless your diet is low in protein. And if you ARE low in protein, you can simply eat protein from food and you won't notice a difference vs. a shake. If you do have a shake, any brand will work for you.

are you hitting your macros??

I assume what you mean by "artificial protein" is real protein but just not directly from food as chicken as protein powder is actually real protein.

The side effects you read about come from EXTREMELY high levels of protein intake. Like you are just downing protein shake after protein shake in between stuffing eggs down your throat. (Aside from specific allergies which is kinda something you have to watch out for with anything you put in your body, artificial or organic grown from your local farmer.)

Where you might be interested in protein powder is when you are lacking for your protein macros and want to get the most bang for your buck without blowing your other macros and overall calories out of whack.

Like for example, an egg. Generally around 78 calories and around 6 grams protein.

Optimum Nutrition Whey Gold Standard: 120 calories and around 24 grans protein.

So, in order for you to get the same amount of protein of one shake you would have to eat 4 eggs and that would net you 312 calories.

The question comes into play if you can get your recommended or target amount of protein in while keeping your other macros and overall cals in check. If you are good at meal planning than absolutely you could. If you have a higher protein requirement bc you are lifting weights or for other needs than it becomes much much more difficult. This is where protein powders can come in and help you hit your goal macros more easily. Think about trying to plan your daily intake so you are at a 500 cal deficit but you want to get 1g per lb of lean body mass. For some of us that is around 150+ g of protein everyday. I am by nowhere close to even good at meal planning BUT with protein powder it makes it much more realistic for me to hit my targeted macros.

BTW, Groupon has an awesome deal on Whey gold standard right now.

My trainer doesnt think I am.
But I need to know how exactly do I calculate that so that I know for sure myself.

Then log your meals and find out how much you average per day. Most women do fine with around 1.5 grams protein per kg of bodyweight.