Grief & Loss Community

I hope for guidance or at least a suggestion as to what kind of help I might seek for issues I believe to have compounded since my father's passing 6 years ago. Before I begin, I will try to make this as brief as possible, please stay with me.
Father - 82 suffered years of COPD/Emphysema, refused doctors until the fall of the year before he passed. I was 42 at his passing. Close knit family, problems like most, more or less than some. Father drank for many years, family struggled during that time. Personally I worried to lose him because of his drinking. He quit on his own later in years, the family had its ups and downs. I think he was depressed because of his illness, he was losing his ability to comfortably breathe and function in general. I was there often for he & my mom. Mom was dependent, never drove, still doesn't drive thus relied on others to help out. I placed myself in the situation of feeling responsible to do so. I believe I have codependence problems personally and perhaps some serious suppressed anger issues.
Six years ago February my father was to go in for angiogram. He didn't have a choice in the matter, pain in his feet became very serious, had gangrene on one of his toes, terrible pain I could see in his face. He never complained, suffered in silence but one could see the toll it took on his health along with the COPY/Emphysema & congestive heart failure. We learned a lot those final months. He should have came home from the hospital 2 days after the angio procedure. Nurses said he they gave him morphine. We thought he would be okay for the night. Found out he tried to get up to go to the bathroom & fell. They discovered tarry stools and preped him for surgery immediately. Found a bleeding ulcer they were unaware of. Surgeon said he died on the table, another dr. brought him back. That was the beginning of his four month stay in ICU. I drove myself and my mother daily to the hospital and back, we were rarely separate, never alone with my fahter. Resentment built, I had two brothers I never asked to help although I expected they would and should on their own. I hold resentment towards them today because I felt they knew I could use a break from being with my mother 24/7, she stayed with me all during that time because she did not drive nor did she have anyone to rely on. (My codependent problem) I couldn't be the cause of her not seeing my dad, she was his wife. So much stress and anxiety filled his room those four months, we were so afraid she and I, my anger became suppressed for fear of the unknown, repressed feelings never able to get out. Where I had been semi religious I've become atheist, i believe in nothing except self, self to be the only thing to rely on in this life when it comes down to it. I find my relationship with my mother is very strained, I continue to be there for her. She has moved closer to me so I could be there, still the brothers are not. Why she depends on me is because I allowed it, I realize this. Sadly she never had the skills to do for herself, my father provided for all of his family, worked hard all the years. Mom took care of house and us but always had to depend on otehrs to help her when she needed to do something. Very low self esteem I have learned these later years but has learned a lot since dad's passing. Still I can feel the anger that feels suppressed raging out of me towards her because she has been so needy and I don't feel I have anything to give. I love her and in my mind I hurt her and I am rude toward her most days. How can I love someone and be so hurtful? I make her nervous because she never knows what to expect with me. I have a problem. How can I find help? What kind of professional do I need to seek please?! This change has been so terribly difficult, life without my beloved father. We both loved him, I feel a true hole in the world, in my life and heart that can never be replaced. PLEASE, needing help, advise. TY