I am so very sorry for your loss. The depression can be a living hell, I know , I've been there in similar circumstances when my Mother passed away. I too gained a lot of weight from eating comfort food. I just didn't care about anything anymore. Recognizing the problem is half the battle. You'll always miss your Mother, there is no doubt about that. My friends and family kept telling me that my Mother wouldn't want me to disregard my nutritional needs and emotional needs. I finally believed them and slowly but surely dug myself out of the hole I'd buried myself in. My family needed me, I needed me. They (your family) all need YOU to be healthy, both in mind and body. I was never one to see a therapist. I don't trust my emotions enough to talk to one face to face, I'd sit there and cry through the entire session and that would do no good. I have no idea if some therapy would work for you but you may want to give it a shot?
Hang in there tibbir, we're all here for you. You can do it, one day at a time. DQ blizzards are a great treat once in a while. Reward yourself with one when you've done well.
As a side note, there is a very caring group of people in the 'bereavement' group you might want to check it out.
http://www.democraticunderground.com/discuss/duboard.php?az=show_topics&forum=323:grouphug:
sincerely.
aA