Thanks for your patience.
Alcohol use often begins as a way to cover over painful feelings. Many adult children decide to drink when they see parents doing so because they assume it is an acceptable coping mechanism. But as most people find, using alcohol adds to problems rather than helps.
It sounds like your father's death was a pivotal time for your family. You mentioned it triggered you and your mother to start drinking. It could be that both of you felt overwhelming grief at your father's death or that his death triggered unresolved feelings about your relationship with him. This may mean that you have issues that you need to work through and once you are able to address them, you will have an easier time staying sober.
Either way, your alcohol use is going to interfere with any treatment you are receiving for your other issues. So becoming sober is high priority. The first step is to get your alcohol use evaluated by a professional. You mentioned that your current therapist is not helpful with your alcohol issues. In that case, you may want to try getting an appointment at your local community mental health center for an evaluation. They offer mental health as well as drug and alcohol evaluations and treatment. If you cannot find the number, contact your local United Way. They are a storehouse of community information and can help you not only find the number, but point you to all of the resources available to you for treatment.
You can also start attending AA meetings. They can offer you support while you work on becoming sober. There are usually several meetings available in most communities. Here is a link to help you find meetings in your area:
You can also suggest family therapy to your mother and brother, if you feel he needs to talk. A therapist can help your family bond together and learn how to communicate with each other. Your mother's alcohol use can also be addressed, if she is willing to become sober.
You also have the option of talking to someone here on Just Answer. Experts sometimes work with people who request more help than just their initial question. You can either continue a thread you start with someone, or request another one. You can also request any expert you wish to work with. You can pay the Expert as your questions are answered. Most people work out a system that both agree on. This would give you someone to talk with as often as your expert can be available.
Also, you can help yourself become sober by learning what you can about alcohol abuse/addiction. Here are some resources:
Alcohol: How to Give It Up and Be Glad You Did by Philip Tate PhD and Albert Ellis
Living With Alcoholism: Your Guide To Dealing With Alcohol Abuse And Addiction While Getting The Alcoholism Treatment You Need by K M S Publishing.com
If you are to the point that you feel you need detox and inpatient treatment, then you can contact your doctor and discuss being admitted. Sometimes this can help you start on the road to recovery.
Let me know if I can help any further,