It sounds like you are very good at helping others but not your own needs. Remember, you are just as important as anyone else. And your mom's death may have affected you greatly. But if you don't pay attention to yourself and treat your issues as important, then you will have trouble healing. People who are empathetic to others often ignore their own needs. It is important to pay attention to yourself, or you become useless to others.
Any therapist, Master's level or above would be fine for you to see. A counselor that specializes in grief therapy would be especially helpful, but not necessary. Most therapists are trained to help those who are grieving. A Master's level therapist is trained to perform full evaluations, diagnosis and provide appropriate therapy. A Ph.D is a therapist with a doctorate. They are also as qualified as therapists just with extra education.
A psychiatrist is a medical doctor that specializes in mental health medication. They can also provide therapy, but mainly they help with diagnosis and medications, if needed.
Regular out patient therapy should be plenty to help you. You can see the therapist as often as you both determine you need to, but once a week is pretty standard.
To find a therapist, you can ask your regular doctor for a referral. Or you can search on line at http://www.bacp.co.uk/ or http://www.cpdirectory.com/cgi-bin/index.pl.
Here are some other resources that may help you:
Healing After Loss: Daily Meditations For Working Through Grief by Martha Whitmore Hickman
On Grief and Grieving: Finding the Meaning of Grief Through the Five Stages of Loss by Elisabeth Kubler-Ross and David Kessler
When Grief Breaks Your Heart by James W. Moore
You can find these books on Amazon.com or your local library may have them for you.
Let me know if I can help any further,