Hi and welcome to hcm.
It can be groin pulling if you remember any trauma in this are. If not, this sounds like inguinal hernia.Check it by trying to cough and see will there be increase in lump size. If yes, then this is likely to be hernia. Other possible causes are varicocele, STD or epididimitis. All thes eyou can check by swabt test and inguinal ultrasounds so do it if your symptoms persist. WIsh you good health.

Hello!

Thank you for the query.

Such symptoms can be caused by inguinal hernia, testicle inflammation, epidydymis, sciatica, urinary tract infection, urinary tract stones.
If the pain is in the groin area, and the bump is present in this area as well, hernia is most probable. You can perform simple test. Put your hand in the groin area, and try to cough while standing. If the pain aggravates or the lump appears, the hernia it is. As you have mentioned that this area is tender, hernia could get stuck. In such case, intestine can get necrotic. This might be an urgent condition.
Testicle inflammation or epidydimis gives pain in the testicle which can radiate to the lower abdomen or to the leg. The testis can be tender to touch.
Urinary tract infection gives also frequent urinating and pain while urinating. Lower abdominal pain or even back pain can be also present.
Sciatica should give more intense pain when lifting extended in the knee leg up. The pain should radiate from the back to the knee and foot. Tingling and numbness can be also present.

I suggest you to visit your doctor right away. Physical examination of the abdomen and groin area should be done. If any doubts, abdominal ultrasound, groin ultrasound, blood work, urine analysis should be also performed.

Hope this will help.
Regards.