Angel,
I remember when Aidyn had his 4month immunisations he FREAKED. He wouldn't let us lie him down at all, as he associated it with recieving the needle jab, and he was distressed all night...
Giving Kynan some Panadol probably wont hurt, and just give him lots of cuddles for the rest of the day... I hope the poor little thing calms down soon.
for you both...