Feeling really upset! Cant stop crying! Help

So I have a cat that I gave up to the humane society because she had tapeworms and can't afford the $30-50 for a visit to the vet.and they came and was picking her up. I asked them how long do you'll keep them before putting them down? And I didn't mean anything by it. I wasn't trying to be rude. But the person snapped at me. And started fussing at me telling me how rude I am. And that is such a rude and ignorant question.and how I hurt her feelings and I really offended her. I broke down crying.and we were talking about the cat a lil while and the whole time I was crying. She apologized. And after she left she called me apologized again and gave me advice and made sure I was okay. And now I have this huge headache. Want to sleep. Can't sleep. I took Tylenol and it hasn't helped a bit. Its been about an hour or hour and a half and i still can't stop crying and its hard to breath. How do I calm myself down????