Hi @Sadsista, welcome to the Forums. I'm so very sorry to hear that you are grieving for your brother. Schizophrenia certainly takes a enormous toll on those living with the condition and on their families. It's incredibly sad that your brother didn't get the help he needed to keep living with the illness.
It's a very powerful mix of feelings that you describe and the pain must be acute. I'm glad that you're looking for support in dealing with this. There are certainly carer organisations in each state which can provide counselling services and other supports. I would hope that they can also steer you towards support groups.
If you are in NSW the organisation is Carer NSW which you can find here. There is also Arafmi NSW which provides services for carers particularly around mental health issues. There is also Compassionate Friends who specialise in bereavement support.
Lastly, you can call the SANE Help Centre during business hours on 1800 18 7263 to get more specialised referral info.
If there are members who are also grieving family members, they may well drop in to share what helped them. In the meantime, please let us know how you go with these organisations and ask us any other questions that may help.