1 - Work out yourself what you want (fuck her/leave her/etc..)
2 - Re-fucking-lax
3 - Don't continue to be an unsociable idiot, talk to people. You said you read
PUA books so pluck up some courage and for gods sake don't think it's somewhat awkward to go to the toilet if passing her desk.
4 - Talk to her. Ask her out for a drink after work. Spend some time together, if not for you to initiate something else then at least go out as work colleagues.
5 - Work out between each other exactly what you want to happen i.e. friends. ** Would be best done after a fuck but since your being damn stupid not wanting to fuck her then..yeah**
6 - Realising that not fucking her was stupid.
Become social and talk instead of email, you walk past her desk to use the can so TALK.
"Hey just a quickie, we've got our break in a few minutes and I'm going to be partially naked in there" - If I had an office job, I'd always have the urge to say that to someone.