Hi! It really sounds like you already know exactly what your problem is. You said it a couple of times in your letter. I need a goal, I have no passion. Your reason for living at this point is the problem or lack of.
My first suggestion is read my article on Life purpose How to Get One. and follow the steps I give that will lead you to your purpose. It sounds like you clearly had many purposes in your life and at this point finding a new one would be the answer.
It sounds to me that in your frustration your over all vibration and the way you are looking at the world could use a bit of a over haul. It is really important to become aware of what you are putting out to the Universe. You want to remember that you are a magnet and what you concentrate on you will draw to yourself.
My last reading suggestion is my article on spiritual awareness In this article I talk about and describe a life changing powerful exercise that for me changed the entire way I look and experience life.
David, after reading the articles, take the action steps suggested in each one. Moving forward for you, it will be about focus, making a plan and then sticking to it. That comes a bit later. Right now you want to start with getting your vibration in a more receptive place.
I would also suggest belonging to a group for people that are starting new projects, where you can stay accountable. A place where you can not only get suggestions and new ideas but a group that will keep you accountable. This is extremely valuable for someone who has a tendency to wonder and not stay on track.
You don't have to let the lack of a certain ability stop you from accomplishing anything you want in life. I do have a Master Mind Group where we do just that. Another place would be Meetup.com. They have all kind of groups where you meet in person and on the phone most of them are free. This should give you a place to start.
I wish for you all the happiness and success the Universe has to offer!