can anyone please help me?

Je
I'm a first time mom and I've been trying to breastfeed my daughter. She's a month now and she's been taking BM and Formula. I've been doing so well w BM up until last week where I've been noticing that my milk supply has been gradually decreasing. 
My daughter sometimes takes my boob, sometimes she just too fidgety & hyper to take it. Then she starts to cry hysterically bc she wants milk. So I give her some formula to calm her down and then I try again w my breast. And she takes some but doesn't get full w my BM. 
I honestly feel so lost and at the brink of crying bc i really want to give her BM until she's a year the least and this isn't helping. I've been pumping too. But idk why my supply has gone down so drastically. I don't even make close to an ounce of BM with both boobs combined. Can anyone please help me or give me some advice? This has really taken a toll on me and I just feel useless and like a disappointment.