How do you grieve? I've just lost my Mum and it's all the little things I miss ... so much.

My deepest condolences. Just feel what you want. Do not place any expectations on yourself. Rely on your beliefs system and let people know it's ok to speak freely with you. Sometimes people are afraid to comfort you because they don't know what to say. This part of life is really hard and only time will heal the wound enough that you can remember her with more joy and less pain.