Feeling Alone For Most Of My Life

I am feeling very lonely today.  Anytime I have time to think I think about how lonely I feel.  I don't have family near me and am still single and in my early 40's and have never been in a relationship.  All my siblings are married and have kids and I don't have anything in common with them. I am closest with my Mom who is in her 80's and when I think about the time when she will pass away I feel awful.  I have one friend from work that I see occasionally but feel extremely isolated.  I don't feel that anyone really KNOWS ME!  I try to ease my lonliness by eating too much, drinking too much and doing anything else the numbs the pain.  I feel like I am going through a midlife crising at this point.  I have stopped going to church and am feeling very alienated from God.  I got a dog and had her for a week and then I got cold feet and had to give her away.  I look at other people and wonder why can't I be like them with family and friends doing fun things together.  I wonder what I will do when I retire and who will look after me in my old age. I hope this gets better because I don't think I can get through the rest of my life like this!