I am close to 30 and not able to ejaculate at times even after 25-30 mins of activity. This happens once in a while and puts me under immense stress when it happens during my wife's fertility period. Is this normal? If it isn't, is it related to Diet, Stress levels or any deficiency? I am currently taking medicine for very High Triglycerides though the cholesterol and sugar levels are under control. I neither consume alcohol nor smoke. Please help.