I've written a trigger in my sandbox to copy the primary contact Role and ID values into 2 opportunity custom fields but it's not firing and I just cant figure out why.

Any help would be appreciated, I'm sure it's an oversight on my part.

Trigger PrimaryContactCopy on Opportunity(before insert,before update){
OpportunityContactRole Roles = new OpportunityContactRole();
for(Opportunity opp:Trigger.new){
Roles = [select Id,IsPrimary,ContactId, Role from OpportunityContactRole where IsPrimary=True AND opportunity.id=:opp.Id];
opp.Name__c = Roles.ContactId;
opp.Email__c = Roles.Role;
update opp;
 } 
}