Breathe sweetie breathe..... Your tensing to much. Woman and men who hold there breathe or tense way to much tend to get the increase blood flow to there head which in turn makes a migrane... Are you a tense person by nature? If so maybe you need to seek medical help to help you relax. Sometimes there are things out there that can help you relax. St johns wort is one herbal way to relax. Becareful not to overdose on it.. Another is warm tea or a warm bath before sex. Theres the old standby drinking alcohol but I dont recommend that as a permanent fix.

Have you tried reading trantric? It concentrates a lot on breathing. Very helpful.

I would talk to a doctor about this- because of the links between ejaculation/migraine/and cardiovascular health... it's worth looking into.