I Recently Took Amoxicillin And Now I Experiencing Itchiness Inside

i recently took amoxicillin and now i experiencing itchiness inside my penis ,especially the middle part and from inside under the vein of the penis head... this has been going on for a while . when i went to the doctor twice he gave me injection for std on both occasion along with the green antibiotic ... i have used citro soda but nothing seems to help as it comes and goes , now its starting to worry me and it gets worse when it is cold as the irritation combines with that of my hernia operation