The loss of a parent is very difficult and upsetting, to say the least. TeenHealthFX thinks you are very normal for wanting to cry sometimes. You need to mourn your father's death and should feel comfortable expressing these feelings. I am glad to hear that you have a good support system of friends and family, but you also need to discuss these feelings with your mother. Your right, your mother is hurting, but you both need each other to get over the loss. This may even do the both of you a lot of good.
TeenHealthFX cannot give you a period of time and say you will no longer feel pain because we all deal with death differently and there is no right or wrong way. You need to feel your feelings. Your father's memory will always be in your heart. Over time, you will learn to appreciate these memories and move through your life.
A loss of loved one can be so hard that you may need to talk to a grief counselor. This is normal and may help you to deal with your issues. Also, you can look into a bereavement support group through your local hospital. Bereavement support groups are for people who are grieving the loss of a loved one.
If you are feeling very sad or depressed or this is too much for you to handle and you have thoughts of suicide, get help immediately from a trusted adult. If you live in Northern New Jersey, call the 24-hour CRISIS HOTLINE at (973) 540.0100. If you live outside Northern New Jersey, call the National Hope Line at (800) SUICIDE.