I don't know where to point you but can give you my experience. My brother and his friend decided one day to hang me upside down in a sewer. That scared me to death. Then they thought it would be even funnier to put me in a metal garbage can with lid and roll me down the alley. Now, this was a common trend with all of my friends who thought it was fun. So while everyone else was laughing I was terrified because they couldn't get the lid off once I stopped. My brother also thought it was funny to try and suffocate me with pillows. We were teenagers when this all happened and I love my brother.
Those experiences started my clostaphobia.
My other phobia started when I was hanging out the second floor apartment window talking to my friends outside. I kept itching on my arms and scratched it like anyone else would do. Eventually it got worse and I looked down and was covered with a huge amount of house centipedes! Babies everywhere! I freaked out as you can imagine. I was a teenager then too.
That experience started my intense fear of house centipedes.
Neither phobia keeps me confined in any way though. I will ride an elevator, I will kill a centipede. BUT, don't keep me too long in a confined space or let that centipede get away or I will break out in a sweat and hyperventilate.
I am also fearful of yellow jackets but only because I am allergic to them.