I'm so so sorry for the loss of your wee boy. You are in the first stages of terrible, terrible grief, and I remember feeling exactly as you've described. dd1 was born at 21 weeks - she had anencephaly, and was our first baby. i thought that I would never smile again, never wake up or go to sleep without crying, never be happy again.
That was June 2005, and I now have a beautiful almost 3 yo dd2, and am 34 weeks pregnant. I am absolutely not the same person I was, and I still think about dd1 a lot, and miss her, but my memories and feelings for her have found a home in me, and don't cause the terrible pain they did. I am happy again - I know there will always be days where I cry for dd1, but I'm glad for that - it doesn't last long, and they remind me that I'll never forget my wee girl.
It does get better - it really does. i will warn you, however, that you may find yourself feeling a bit better in a week or so, and then suddenly have a big crash - this is apparently due to a very cruel change in hormones, which can make you feel very emotional and weepy again.
Don't feel shamed by feeling angry - it is an absolutely NORMAL part of grief, and something that maybe you just need to feel right now to help your mind deal with such a terrible loss.
It will get better - the brighter moments become hours, and then days, and get closer and closer together, and you will find a safe home for your feelings and memories of your beautiful little boy.
I found the SANDS forum invaluable - didn't discover it until I was pg with dd2, but it was a godsend. MN is also brilliant - keep talking and talking and telling DS's story as much as you need to. It will help.