White spot on 1 tonsil, was sore that side yesterday now just feels swollen. no fever but generally feel unwell with body ache.

Tonsilitis: What you are describing could be caused by a number of things--strep throat certainly, which would require antibiotics. But many viral infections can cause symptoms like this and in particular mononucleosis from Epstein-Barr virus, and other related viruses like CMV can all present this way. There are throat swabs for strep and blood tests for a number of viruses that your doctor can perform.