Welcome to the forums and I hope you can stay around to continue to post here, as you are welcome 24/7.
It is a big step to ask for help or guidance, so congratulations on making that first step!
I would recommend speaking to a GP or a mental health professional to help guide you in what you may be going through, if you deem that your anger may be unintentionally hurting those around you.
However, in the meantime, if you need anyone to talk to or if you need support, please contact Beyond Blue Support Service on 1300 22 4636 or on Webchat 3pm-12am AEST at www.beyondblue.org.au/getsupport . There is also Lifeline on 13 11 14 or the Lifeline crisis chat 7pm - 12am at https://www.lifeline.org.au/crisis-chat/ .
I would also recommend visiting these two websites as they help to shed some light on anything that might be causing your mood swings. But remember, take the information inside these articles with a grain of salt.
Hope this helps!