Hello, I'd like to help you with your question.
I am sorry to hear about your sister. It is very understandable that you want your family and psychiatrist to hear and understand your thoughts and feelings about what happened to your sister. It can be upsetting when those around you do not offer the support you need, especially when it comes to the loss of someone so close to you like your sister.
Although it makes the grieving process easier when you have support, it is not necessary in order for you to grieve your sister. You can go through the process with support from other sources. If you are in a relationship, ask for your partner's support. Also, rely on support groups for bereavement, either on line or in person. Here are some resources that can help you get started:
As you work through your grief, it often helps to talk about your loved one and maybe even write a letter to them expressing your feelings about losing them. Expressing your feelings in other ways is important as well. Anger, crying, trouble sleeping and eventual acceptance are all part of the process.
You can also let your family and doctor know that although they do not agree with your version of your sister's death, you choose to believe it. It is how you feel and it is just as valid as their feelings about your sister's passing. When you express how you feel, be gentle yet firm. It shows your family and doctor that you believe what you say is important.
I hope this has helped you,