I totally understand your fear... before I did my first flush I was really scared too and put it off for 4 months before I finally worked up the courage. During my first flush I was also really anxious which I don't think helped in releasing the stones.
I'm about to do my 4th flush next week and I've never expeienced any complications (except for lack of sleep when I flush!)
I used to be really scared that stones would get stuck. But on my last flush I released about 70 stones and 10 of them were about 3 cm long and I couldn't feel a thing as they were travelling down the bile ducts so that's pretty much taken care of that fear...
Also I used to be scared of drinking all that olive oil - but really, it's not that much - it's about half a cup. I use the first cold press that way I know I'm getting the best out of the good oils.
I really relate to you so much, I used to be so scared but know I think nothing of it. In fact I look forward to my next flush.
Also I flush to clear up Acne that I've had all my life (I'm 30 now) and my skin gets better with every flush. And I'm so thankful!