Hello.Thanks for the query.I understand your concerns. Brief answer: Anxiety,Emotional disorders,Low testosterone levels,Expectation of performing well,Relationship problem with the partner,Excessive masturbation are the usual causes Detailed answer: Yes.From the history,it seems to be a sign of premature ejaculation.According to me,ejaculation immediately after the sexual stimulation or before a person wishes to ejaculate can be called premature ejaculation.If i were your physician,would advise for certain initial investigations like fasting lipid profile,urine analysis,serum testosterone and prolactin levels to rule out any androgen insufficiency,and later pudendal nerve latency test, IVEL(Intra vaginal ejaculation latency time test) to proceed further.Hope i have answered your query.If any further questions,wish to answer you.