Most people organize some form of refreshment after the funeral. This can be a good way of accepting condolences from those you were unable to speak with during the actual service. By offering refreshments you are showing that you are willing to share your grief with those who are also suffering through their own loss.
Enlist the help of a friend or two. You may feel that you will be able to cope but having support close by will be very helpful should you find that you are feeling too upset to appear.