Is it normal my friends have been like this to me?

I dont know what to say...
I guess I will start with a severe problem of the grass is always greener on the other side. I make a decision then spend my time realizing what a mistake it was until I reverse the decision and do it again. I have two great girls but didnt fight there mom for much parenting time even though I really wanted to have the kids more. Now I am stuck with every other weekend and a few hrs during week days. I am trying to make it work and am great when the kids are around but fall into depression when they are gone. I decided to go back to school and am earning strait A's the past year (first time ever.) I am trying to keep busy with projects around the house and school work but I never feel very happy. Plus I am starting to run out of room in the backyard to bury the dead hookers. I used to be so different than I am now and am finding it difficult to keep going. I know the kids need their dad and I am trying to do the best I can. I know I am being a great dad but after a weekend with the girls, and their mom picks them up I feel as empty as ever. Hookers help fill the void, but after I end being lonely again. I try to date but dont feel even near emotionally available or worthy of love. I have started smoking some but keep it hidden. I try not to drink (never do with the kids) but I cant sleep if I dont have a couple beers before bed. Is it normal that I stick the beer bottles up my ass once I am done drinking them? I cant shut off my mind. I just toss and turn. I lost a few close friends over the past few years and I dont feel like hanging out socially with the friends I have.