http://usagib6danuxndqle3usrweloyskdeoelthqizr6wl7u3tnsmfwho5ad.onion/v/2K8TWRSC
You could do is break the torches of the places aren't the exit and then look for pockets of light (this is mainly useful if you are trying to look for an exit in the ceiling).
You could also kill yourself with fall damage, water, or by placing blocks inside yourself (suffocation, do this with sand or gravel since you can't break stone with your fists).