Brief Answer:
You are suffering from a condition called erectile dysfunction .

Detailed Answer:
Hello Dear
How are you ?
I am Dr Rahul Rathee . Well from the details you have provided it is clear that you are suffering from a condition called as erectile dysfunction .
In this condition the erection of penis does not sustain for long enough to perform sex .
There can be many possible cause for this dysfunction .
You need to visit a UROLOGIST who will ask you to get some laboratory tests to find out the precise cause of your dysfunction . The cause of erectile dysfunction is due to poor blood supply in the penis which can be due to various underlying reasons . A urologist will perform clinical examination and required tests to determine the possible cause in your case .
Now a days there are many drugs available for treating this condition , such as -
(1) Sildenafil
(2) Avanafil
(3) Tadalafil
All these are prescription drugs and needs to be taken under the supervision of your prescribing doctor .
There are other treatment options are available which depends upon the underlying cause of erectile dysfunction , such as -
(1) External vaccum pumps which are applied on penis before performing sex . These pumps increases the blood flow in the penis leading on to erection
(2) Intra-penile injections
(3) If there is correctable cause , surgery is another option to correct the underlying cause .
So , you need to visit a urologist for detailed evaluation and required treatment
I hope i have answered your query to your satisfaction but if you have any further doubts , please feel free to ask me .
Take Care Brother
Dr Rahul Rathee .

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