I have tonsillar hypertrophy. For the past 24hr I've had an sore throat, no appetite & a what looks to be a blood blister on my tonsil. What is this??

Tonsil lesion. It could be a small blood blister, could be a dilated blood vessel on the tonsil, called a varicocele, which is a normal variant. Sometimes you notice things that have been there because your attention is drawn there, in your case due to sore throat. Doesn't sound concerning to me, but you should see an ENT doctor to check it out.