Think of everything you ever wanted to do, ever, but didn't do, and then try hard to remember why you didn't do those things.
Think very hard - force yourself to remember what excuses you came up with, the convenient rationale, contorted logic or pathetic self-defeatism you employed to convince yourself that whatever it was you wanted to do was going to be too difficult, or was unattainable, or was going to be too much of an investment or required too much patience, or you didn't possess the talent, skills, or ability necessary and it was just too far out of your reach.
Then think of all those people who did exactly what you wanted to do. You most likely know of several people personally who have done or are doing something you have always wanted to do and you have compared yourself to them and their efforts, and have said: "I can (or could) do that" Probably with an exclamation point added for emphasis.
You probably lost count of how many times you have said to yourself, "I could do far better than that" when witnessing some successful person's accomplishments - we've all read crappy books, watched crappy movies, looked at crappy art, listened to crappy music, worn crappy clothes, endured crappy performances - all while the crappy stuff was earning their creators a comfortable living if not outright fame and fortune.
Or at the very, very least, rewarding those creators with the satisfaction of knowing they did exactly what it was they set out to do.
So why haven't you done any of those things you've always wanted to do? Why have you allowed yourself to be talked out of adventure after exciting adventure? (Usually by yourself) Why have you failed to follow through with all those dreams? Is the risk that much greater than the reward? Hell, if what you have always wanted to do is simply write a book or take up sculpture, how high can the risk be? So you write a book no one wants to read - at least you wrote a book! That's more than a whole hell of a lot of people who have ever set out to write a book ever accomplish!
BTW, the figure "whole hell of a lot of people" is probably a lot, but seriously, there is no way to accurately determine that number, so the vague "whole hell of a lot" will have to suffice.
The thing is this. At some point you are going to have to realize that procrastination, excuse-making, living in fear, etc., is something you actually can stop, and you are going to have to just knuckle down and go all Nike commercial - just do it.
Look, there is no person on this planet who doesn't better understand how difficult it is to "Just Do It." For years I've wanted to shove that slogan right up Phil Knight's ass, but the fact of the matter is, there is a ton of truth in those three simple words.
Dealing with ADHD or OCD, struggling to just get through the business of staying alive on a day to day basis, being limited by lack of funds, resources, time, ability, etc., those are all legitimate concerns...but time after time people have overcome those and many more limitations and accomplished good things, great things.
Making the jump from dreamer to doer doesn't require magic or extraordinary good fortune. It does however require taking action, which, yes, means you might have to work.
Yeah, you have probably worked hard in the past in trying to accomplish something and think you failed at it, but remember that old saying "The only failures are those that stop trying?" That old saying is true. Pick up at wherever you left off on what it was you were trying to accomplish, and just continue trying.
Or start fresh - whatever works for you. Just continue trying.
Continue trying. Trying leads to doing. Doing leads to accomplishment.