I try not to deal with people who don't understand. If I cannot keep up a relationship with someone, for whatever reason, then I "give up" that relationship and when they call and ask me out, I'm unavailable. If they do not understand my problems now, then how can I have a very productive relationship with them?

You do not have to excuse yourself/your behavior to other people and explain. You see how well things go with your one friend who knows to see you in a pattern you can cope with; for now, that is what you want so I'd go with it.

Or, if you wish you could see this other woman who does not understand, I would "use" her to practice making plans or experience being anxious and living through it, etc. so your world does not get any "smaller" that you get stuck in your house full-time. If that alarms you too much, maybe ask the woman you trust, the pattern woman to mix it up next time, to pick another restaurant, etc.?