How to get purge of fright when making decisions ?

I have this big difficulty of not being able to compose decisions. Particularly big decisions. It's like I want a bit and I work to get it and when I have an opportunity finally, I freak out. I begin thinking about what I might drop, that things won't work out there, I won't like it, and I’ll regret it and many more. I think this is usual for many people, but why if deep inside I wanted it, I made a decision to go for it and just when all is left is to skip - I back away. Like the thing with moving... I wanted it for a long time, but still can't do it, the thing that always makes me irritated is about leaving my parents and I think about who'll take care of them when they are really old...and this makes me feel so guilty (even though both my parents moved away to different city from their parents and they support me in my decision), but I keep thinking about it over and over again, making myself feeling really bad and sad and that's what’s share me back...

I just want to know how to break this "wall" that I always bump into...

I read Steve's articles that are really cheering: "Regretting tomorrow" and "Making decisions that stick", I get encouraged when I read them, but then it all comes back...

I really wish I could stop perturbing about the potential too much...

I want to learn how to bungee jump without spending 2 hours at the top there thinking about how'd it feel, will the lash split... and just fly, because if I'm standing there with ropes around my waist - that's what I wanted to do..
Thank you

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Just remember that death isn't the end, it's the next great adventure... so have a go here while you still can. Regret in the afterlife sounds/feels like it could suck eggs.

By growing the female equivalent of cojones. ;)

But really, I reckon the best medicine for this is to forcefully expose yourself to such situations rather than curling up and avoiding them at all costs. Maybe repeat them after you've done it once, wear down the barriers.