Hi granite,
I completely understand about the thoughts and feelings that constantly play in the mind. I have similar thoughts of unworthiness. Often feeling like I'm a problem for the people around me. Feeling like I just can't do anything right. It's a nightmare. Currently I am practicing tuning out these thoughts / feelings, and it helps to make a list at the end of the day of the things that did go right (especially if someone else commented on how good I did).

I also realize that having a big goal to work on over this year can be daunting. Mine is to simply breathe - especially during times of stress. However, I am working on some small daily tasks such as brushing my teeth before bed, having a cup of tea in the evening, going for a walk around the block each morning, etc... If you like video games, there is a great free online game that you customize with whatever tasks you want to accomplish, along with habits you want to create and break. By doing these tasks you earn experience points and gold (which you can spend on rewards). You build up a character, which at level 10 you can specialize as a warrior, mage, rogue, or healer. There are guilds to join and quests to accomplish. It has really been helping me. The site is called HabitRPG - maybe it could help you too!

Good luck and best wishes!