I have experienced multiple forms of death and gone through the grief, from experience I can tell you that it will feel unbearably awful and you might want to drown out the pain with substances, don't it will only make the process more painful. you cannot cheat the grieving process you can only delay and prolong it. Everyone experiences grief differently and goes through it at different paces, do not let anyone tell you that you are taking too long or grieving wrong. If you experience panic attacks or anierty attacks accept that it is happening, that you will survive it , it will pass you just have to let it happen. I really wish I could offer more than just advice on how to survive grief and anxiety, know that there is a person who will never meet you that cares about you and wishes for your pain to end and your life to regain joy.