Oh dear, no you are not alone. Many people (me included) have been through "bad patches" for want of a better phrase. I am not trying to guess you, I promise! I felt very depressed during my pg (no particular reason, just think that the combination of hormones and having been stressed out at work for a few years was bad for my peace of mind), so I can identify with feelings of hopelessness. An unhappy childhood doesn't help matters at all - if you lack the basic reassurance that you are loved and lovable that makes dealing with the stresses of day to day life that much harder. It sounds like you are suffering from a degree of depression or anxiety at the moment. Would you consider going to a doctor and trying anti-depressants or counselling or some form of cognitive therapy. Cognitive therapy is good because it teaches you to think more positively, and have a more realistical view of yourself, without wallowing in your past iyswim. If you don't want to go down any form of medical/treatment route there are little things you can do to make yourself feel better; exercise/yoga-meditation/eating properly/sleeping properly/getting a break from your responsibilities. Another thought - it may be sensible to go to your GP anyway to exclude a physical cause to your symptoms - hormonal contraception, thyroid problems or iron deficiency can cause symptoms of depression.
I am off to bed now, but will be around tomorrow evening. If you ever feel absolutely desperate please phone a friend/family/the Samaritans if necessary.
take care