How Can I Let Go Of This Anger?

Recently my father passed on which has been very difficult for me. My financial situation has not been the greatest and I could not afford to fly home to Hawai'i for his service there, we did however have a service for him here where he had just moved a year ago with hopes of eventually retiring and enjoying life in the north. I'm glad that I had that chance to be there, thank God..however, my family that flew here for the service left immediately after for home in Hawai'i and my mother (who lives here up north in the same town as myself) followed them while knowing that I couldn't afford to join them. Now keep in mind my Mom and Dad have been divorced since the late 80's and my Dad was happily remarried for almost 18 years. I'm so angry..I felt as though my Mother was being selfish and making decisions based on her emotions as usual. How do I cope with these toxic feelings? I am sick right now..the sickest I have been in years and think it has much to do with that among several other circumstances. I also think I am finally ready to detox as soon as I feel better. Anyone out there have any suggestions?