It seems to me that you may be stuck in the stage of anger
A lot of times we think of grieving only if someone passes away. But we are grieving losses every day. As little as someone cutting you off in a car or getting in front of you in a line to feeling the loss of love or the “normal” life you wished for. Sometimes the losses are so small, we may grieve quickly, but some losses are so huge that it can seem overwhelming to grieve them. It usually goes back to those coping skills that we learned in our families. Was it okay to get angry? Was it okay to be sad? Sadness can be anger turned inward because we weren’t allowed to be angry outwardly or vice versa. Depending on which stage/s we are stuck in, we have the other stages to grieve. When things happened a long time ago we tell ourselves that we should be over them when in fact we never grieved them at all. Allow yourself to be sad, angry and questioning. And when you get to a question that the answer is"I don't know", kick it out of your head. It does no good to wonder what could have been. It’s when you get through these stages that you get to acceptance, not necessarily forgiveness (that has a stigma for some people) but to accept it as a loss.
We sometimes get stuck in some of the stages of grieving: Denial or Numbing, Sadness or Fear, Anger or Irritation, Bargaining (Questioning) or Anxiety before we can get to acceptance. Do you find yourself getting mad or frustrated easily? Do you often tell yourself nothing matters and say whatever? It sounds like you have suffered a loss or quite a few losses.