Hi, thank you for using health care magic. I can understand your concern. Masturbation as such does not produce any sexual dysfunction. It is normal practice in most of the male and no adverse effect have been proven. from the description of your symptoms i learn that yo are suffering from low confidence rather then any thing else. There is technique called start -stop technique , and squeeze technique which can offer you more control over ejaculation. this will reduce premature ejaculation over time. For erection problem spent 15 to 20 minutes in foreplay. sensate focus training will help you in getting proper erection and focused intimacy. Do not worry about performance and enjoy the intimacy, this will reduce both erection and premature ejaculation problem. Isolated incident of loosing erection can occur in male s sexual life , this will come and go , worrying excessively about it will increase your performance anxiety. Medicine like sertraline , escitalopram are also useful in reducing premature ejaculation , this medicines are usally prescribed by psychiatrist for treatment of depression but for your condition they are also useful. So i would suggest you to consult psychiatrist for further help if needed. Psychiatrist can also help you out through behavioral therapy in your condition. Hope this will help you. Regards.