Hello Friend, Good that you are seeking a help here. Such mood swings are expression or outburst of stress. You be stressed out due to studies or careers or relationships related issues.
Don't worry, these are just like any other physical illness and can be addressed through counseling session and few lifestyle changes or self therapies.
Next Steps
Consult any psychology counselor locally or online through Practo. Feel free to reach out to me online for further assistance.