I had lower back pain,skin felt warm,nauseous,painful urination,and a loss of appetite on day 1.day 2 symptoms are gone except for painful urination.

Bladder infection : You likely have a urinary tract or bladder infection. Women are prone to urinary tract infections because the tube that goes bladder (urethra) is short. Frequent sex can push bacteria up into the urethra and into the bladder. See a doctor and start treatment to prevent the infection from spreading to your kidneys. Urinate immediately after sex and drink lots of water to prevent a recurrence.