I'm a 19 year old male. I'm having premature ejaculation. Not only that I ejaculate too soon (within 15-20 secs) but also I'm losing my erection immediately after ejaculation. I also feel sometimes that I'm not attaining a stable erection, because every time I get aroused my penis lifts only halfway up stable, then it just thuds up and down and doesn't stay upright steadily. I'm so much worried about this. Pls suggest some cure for this.