Mood swings do happen before a cycle so what you are experiencing is normal before your period. Now, if you are still experiencing that after your cycle ends, that is not normal, and you might want to get professional help or medication. Sometimes simple things like exercising and watching something funny that makes you laugh can help your emotions.
This is common for most women but the degree how bad the depression can be much worse for some women. I'm SO sorry you are one of those. It's hard, sweetie. I understand. There are psychiatrists that do treat women with this issue. Have you ever heard of Premenstrual Dysphoric Syndrome? https://www.womenshealth.gov/menstrual-cycle/premenstrual-syndrome/premenstrual-dysphoric-disorder-pmdd They normally treat this. The ways that they do are often selective serotonin reuptake inhibitors or SSRI's (like zoloft, prozac, etc.). They also may start a woman on birth control pills which can help. And lifestyle things like stress management can be important. Yes, hormonal changes during the cycle are thought to play a role. Which is why birth control that regulates that can help.
Here to talk if you need it.