Thanks for posting your query.
As you have had sprain/strain on lower back, it is possible that strained muscle has irritated some vessels or nerves. It will go away with time, you can take muscle relaxants. As far as your swollen tongue
and lips are concerned make sure what drugs you have been taking recently, usually it is caused by drug reaction or food allergy
Relieve from anti histamine
suggests you have got allergic reaction
Contact your doctor and notify your reaction and drugs you have been taking.
Hope it helps.