I can relate to what you're going through...it's kind of like laying out the story plot for a book but never really getting started on it, or just worrying yourself to death that it won't turn out the way you want it too...just futile.
In that case, don't create long-term goals. Focus on what you're going to do, let's say, for the next hour. Create a simple list, for example
To Do List
5:00 p.m. - Become a couch potato and watch TV
5:30 p.m. - Take a walk
6:00- Go on suicide forum and rant and rave about my day
Even though it's nothing special, start by planning very simple things and try to carry them out. Sooner or later you'll get used to it and add more important plans more ahead of time, and eventually you can create a long-term goal that you can carry out. You'll be so busy your anxiety will dissapear!
Also, you should consider keeping a self-reflection journal. Every day whenever you feel like it write down how you feel, and why. It's amazing because it puts things into perspective, it's also a great release...
What I usually do is create my own inner sanctuary. It's interesting because you can create your own surroundings, even include people, and activities. So when you're really stressed out and you feel like crap you can take a moment to close your eyes and imagine yourself in your sanctuary, just detach yourself from the world and everything/everyone around you, even yourself.
For example, a lush garden full of tropical plants and animals, cascades. Imagine crushing the wet grass under your foot, inhaling the cold crisp air, and hearing the birds sing. Or you can even imagine your own preternatural futuristic city, but just like actual construction this might take some time. The human mind is capable of so many things...we barely know half of what we are capable of.
Oh, and if you ever want to store things in memory, create a memory channel. Like imagine a television screen, and for every channel store certain memories in there, like channel 1, memories of places you visited with your family, and channel 2, memories of school dances, etc. Or you can create your own house full of memories, and in your mind open each door leading to a certain memory you want to treasure.
I hope this somewhat helped!