I agree you need to go out with your mom today. You will probably be tired because of last night and you may feel like crud but you need to go. One thing I've learned is that the more we cave in to this, the worse it gets. The more we fight back, the stronger we feel. When you're feeling like caving in, think to yourself, what is the worst that can happen? You'll go out with your mom and be tired, you may get a little dizzy from being tired, maybe get anxious, maybe have a panic attack. But, you won't die. Chances are very high that no one will even notice if you are feeling anxious or panicky. If you get to feeling panicky while you're out, just remember that's all it is and you've done it so many times before that you will get through it this time also. You will be ok!
Congratulations on getting through your panic attack last night by just ignoring it - that's fabulous! I get panicky at night also because I've had some insomnia problems lately. I'm starting to get over it though because I've been using the same logic with myself that I talked about above. I tell myself, so what if I'm up late or don't get more than a couple hours of sleep. It just means I'll be really tired tomorrow, but in reality, that's ok. It's not going to kill me. It's starting to help and I am finally starting to get some sleep.
Good luck today! Try to enjoy and remember that if you start feeling anxious, you will be ok. You are stronger than you feel - I promise!