If you want to get rid of those worthlessness feelings, try using EFT, there are many good EFT videos on yotube and on
Tapping.com - Free EFT Videos - Emotional Freedom Technique, i used it and it has helped me a lot, and not only me, thousands and thousands of people are benefited by it.
EFT is an accupressure technique, it looks weird, but its often very fast and effective, you should really invest some time to do some EFT rounds, youll feel so much difference after you do.
If you wish i can give you some advice on how to do it, im no expert, but have been doing eft for months, some issues are easy to get rid off, some arent.
Jesus bless you, good luck.