What are the symptoms of stress?

Last night after I left my dads house I got a huge headache. I took a pain reliever, and it went away, but then I started feeling kind of dizzy, and when I walked I felt like I was too heavy and my body was like dragging me down. I went to bed, thinking I'd feel better when I woke up, but then I woke up at 5 in the morning and my heart was beating really fast, and my throat was sore. I couldn't breathe, and I felt horrible. I called my mom, and she told me that it's stress. Is that what it is? I'm confused and I feel like crap. If it's not stress, what is it? What do I do?