Sir my dick is small and finsh time 50 sec tell me...

regarding penis size :
What is the normal penis size in relax and erection time :
1. erection : 8-18 cm
2. relaxtion : at least 6 cm
How to increase penis size ?
- the only options to increase penis size in effective ways are the surgical options , which are :
1. there is a surgical option that may increase you penis size about 4-6 cm by cut out the internal tendons that connect pelvic area to your private area and leave bigger space to penis to increase 
2. there is a plastic surgery that increase penis size by implanting silicon implants in the upper areas of penis goes into the internal area of penis and it increase penis size around 6-8 cm
regarding premature ejaculation :
What are the treatments of Premature ejaculation ?
1. following sexual intercourse techniqes that prevent or delay ejeculation 
2. you can use some topical medication to delay the sexual sensation in your private area such as lidocaine 
3. some of erectile dysfuntion medication may help you to prevent premature ejaculation such as Sildenafil ( viagra ) , tadalafil (cialis ) and Vardenafil ( levitra 
4. you can also use some anti-depression medication which are prescriped by specialist doctor and cause delay ejaculation as a side effect such as  such as escitalopram (Lexapro), sertraline(Zoloft), paroxetine (Paxil)
General advices to increase your sexual ability :
1. following the healthy and appropriate way to do the sexual intercourse with your partner 
2. having a regular healthy diet 
3. doing exercises and give up bad habits like smoking and drinking alcohol 
4. avoiding stress and anxiaty sources 
- please avoid products or tools that claims it can increase penis size because its not medically approved and lack of long term effectiveness