Sorry to hear your news. But, FWIW, you’re in good company. Losing one’s job doesn’t seem to carry the stigma it once did. Heck, I’ve been laid off a few times (unstable high-tech companies), so I may be qualified to answer your question:
Make an unemployment insurance claim. I don’t know what the unemployment insurance situation is like in your location, but in mine, there is a waiting period for all claims that begins the day you make your claim. The sooner you file a claim, the sooner you can begin to wait, and thus the sooner you collect. And once you collect, you can cover the rent, food, and perhaps even portions of school loan payments.
Stay busy. It doesn’t matter what–your bookstore idea is a good one, or there is volunteer work for a local charity, or something else that will get you out and keep you occupied. If the hours are flexible, so much the better: you can arrange job interviews during business hours. What you want to avoid is bumming around the house brooding on your situation; staying busy keeps your mind focused on the tasks immediately at hand and not on what happened to you.
Don’t be afraid to take any job if it comes to that. In other words, if you’re trained as a rocket scientist and no jobs are available in that field, but jobs are available digging ditches–well then, dig ditches. Call it temporary, call it a stopgap, call it whatever you like, but you’re going to have to pay your way eventually, and the money earned from digging ditches can be used for the same purposes (i.e. rent, food, etc.) as that earned from rocket science. Keep up with advances in rocket science through professional organizations and publications during this time; then, when jobs in rocket science open up, you can go back to working in that field.
In the past, I’ve had to take jobs that I never thought I would. But even though I kept up with my field at those times, I met some great people in the blue-collar world and learned some skills that may come in handy if there is a next time.
As for the SO birthday question, I think he will understand if you cannot do what you originally planned. I know that when my fiancee (now my wife) was in a bad patch, it meant a lot to me that she just remembered my birthday with a card. I’m sure yours would understand too.
Hope this advice helps. Good luck, Francesca!