Welcome to HCM.
Pain in testes can be caused due to many reasons. Pain in testis could be due to an infection like orchitis
, trauma, torsion of testis ( causes decreased blood supply to testis), hernia
Based on the information provided, the pain in your case could be due to strain( due to excessive masturbation
) or could be due to torsion or could be due to tight innerwear.
It is very essential to wear a correct size of underwear, either tight or loose underwear can lead to problems.
Coming itching of scrotum- It is a common problem. As areas of groin and scrotum sweat more, it causes itching. The redness
is due to excessive scratching. Keep the area as dry as possible. In case if you have any nodules or scaly lesions on scrotum,it could be due to a fungal infection
Coming to erection problem,it is due to stress. Just stop worrying and everything should be normal. I dont know what amount of semen you have been considering less. The normal volume of semen is 2-5ml.
Finally i would stay the pain could be due to abnormal posturing while either having sex or masturbating, so try to change that.Keep your groin area clean and try to wash with water bfore going to bed and keep your scrotum and groin area as dry as possible, if possible try to avoid wearing underwear at nights.
In case if you still have doubts, just get an ultrasound
done to rule out other possibilities and meanwhile clear your doubts.
Hope you got the answer you were looking for.