My lower back, lower abdomen and heart really hurt/feverish, nausea, chills, vomiting, trouble sleeping and walking, tired, dizzy. What can this be?

See doc. Multiple reason can cause these symptoms. Check with your doctor. If your symptoms getting worse, may go to er.
Lots of causes. Fever ; chills suggest infection. Being sick could explain nause ; vomiting. Dehydration from throwing up could explain feeling tired ; dizzy. Unfortunately, w/o exam ; tests, we can't diagnose infection online although kidney infection ranks high on list. Best to go see your family doc immediately (or urgent care/er if s/he isn't available). Good luck!