Have you ever felt like you are in a standoff with yourself? I have been thinking I need to find a new job for about a year and a half now.

Here are my issues with my current job:

1. Anxiety to the point of not getting anything productive done 2-3 days a week (note, I am writing this while at work)
2. My coworker drives me insane. She basically purposefully spirals her life out of control and lives far beyond her actual affordable means. And then complains about it. I cannot understand it and listening to her is driving me insane.
3. I was originally hired for customer service (and selling to existing customers when the opportunity arises). My boss is ambitious and wants more sales but I just don't have time on top of servicing all our customers. Because she has been unable to find someone for sales that has lasted longer than a few months, a lot of the pressure is being put on me to make more sales. I had been clear that sales is not what I really want to do in this field.

Some of the reasons I've stayed:
1. The pay isn't terrible. I make $15 an hour (although it is essentially a salaried position) plus commissions and renewal commissions.
2. I have guilt at the idea of leaving. Leaving would put my boss is a bad position as my coworker cannot do what I do officially.
3. My boss finally got us health insurance last year. While I'm paying for half of it, it is still less then what I was paying on my own. With the market as it is, I am nervous to have to find insurance again on my own (even if it is temporary).

And while I'm having all these issues, I still find it hard to motivate myself to apply for jobs. I don't know what I want to do and sometimes jobs I probably would be good for have almost unreasonable (by my perspective) requirements for the job.

What advice do you have to get over the mental block of both leaving a job and job hunting? And in the mean time, what do you do to deal with work related anxiety?

(also, please advise if I have put this in the wrong section)