Meloxicam Side Effects

Patient: Yesterday about 3:30pm I took my first dose of Methocarbam 500mg and Meloxicam 15mg for muscle spasm from a car accident. Around 7:30pm I started itching and turning red. By 9:30 the itching had relieved but my face was red and was swelling. By 11:30pm I was worried and called the pharmacist who suggested Benadryl. At 1:30am I took a 25mg of Benadryl and another around 3:30am. It is now 11am and my face is still swollen. How long do these side effects last and should I keep taken the Benadryl?

Symptoms: Swelling of the face.