Rituals, Weakness & Strength

So, my co-worker who is going through some major issues at home has asked me to go out with her for a drink tonight. She also mentioned that she'd like to start making this a "ritual". Ugh, it's stressing me out.

I know she doesn't have anyone else in her life besides me, her husband and her therapist. Because of this, I feel kinda obligated to say "yes." However, there are a handful of reasons why I want to say "no."

-I only get a certain amount each week for my "Mad Money" and I don't necessarily want to spend it going out with her.

-I am trying really hard to not drink/eat the wrong things. I'm on Atkins and extra carbs don't really fit the lifestyle.

-I have gotten too close to her for my own good, mainly because I felt bad for the situation she's in. My position at work doesn't really allow me to be close friends with employees. It's expected that I'll keep that them at a distance.

-Last, but not least, I don't like to be locked into frequent events. In my previous life (when I was married before and lived on the East Coast), I found that I over-committed myself and was stressed with promising so much to so many people. Since moving to CA, it's just been my hubby and I. We both really like it that way. We just kinda keep to ourselves and do our own thing. The idea of having a weekly commitment is stressing me out.

As I re-read this, I know I should just tell her "no" but I just told her "yes." This is one area I need to grow in. However, it's so hard for me because I know she doesn't have anyone else to turn to. I just can't be "her person." Do you know what I mean? I have a person. I can't commit myself to making her happy.

I'll go tonight because I said I would, but somehow I need to get the point across that I'm up for an occasional night out but it can't be a planned weekly event. Any advice is welcomed :)