oh wow, yes, I go through this same thing! I have figured out that one of the hardest parts of showering is the fact that it drowns out any outside noise so I won't know if something is happening, someone is coming into the apartment, etc. Of course I have the doors locked, I ALWAYS have the doors locked, but it doesn't take away that irrational fear.

I have been known to go a long, long time without showering for this very reason. :/

Also have the same issue with vacuuming, I need to be able to hear what is going on around me or I'm just too scared

i find this interesting as i have a fear of the shower (sometimes, not always) but it's much more mundane - i'm always afraid that i'm going to slip and fall badly. i didn't shower for several months because i was terrified (obviously i took baths, etc, but even then i used to worry about getting in and out). and getting in still makes me jump - that first sensation of being under the water makes me gasp and catch my breath, which is a hideous feeling if you're already paranoid.

i've often wondered if it relates to the fact that i never took showers as a kid - always baths. and i hated bathing then, as my mum always used to run it too hot, but when i moaned she would always just make me get in. i wish she hadn't, as i feel that has a lot to do with my general phobia of bathing etc.

i've said to myself that i'm comfortable in my own skin and that i like smelling like myself if i don't shower for a day. but then i think i'm kidding myself. i'm jealous of people who don't have issues with it, because it seems like a totally lame-*** thing to be afraid of.