Well I'm all for meds when needed, if your mood swings are due to depression or anxiety. So if that's the case, I would surely go to the doc. I don't have anything to offer about the natural supplements.
But what you describe is a reaction to your toddler. Which is totally natural and no amount of meds will help that!! (otherwise they'd be flying off the shelves!).
I would say that even if you do need meds for any kind of condition, you need to figure out a way to deal with your DD. Love and logic is a great place to start. Usually, tantrums can be remedied by ignoring them or staying calm and distracting. I don't know enough about how long she's been doing this or what sets her off. I don't presume to give a short answer or tell you things you may have already tried. But I do recommend getting some books on toddlers to see what works for you to manage her behavior.
I'm sure it only makes things worse to have DH get mad at you. Everyone has different temperaments. Some can stay cool easier than others. There is no good or bad here, it's just a matter of how you manage things.
So remember that you are not DH and you have your own way. Get some parenting books to deal with DD. And if you still need meds, get to the doc- maybe tell them you'd like an herbal remedy before rx? Good luck to you.