Well, groin strain is usually due to a muscle pull or muscle strain in the thigh. However, if you have tingling on the head of penis, then may be you have a pudendal nerve entrapment, inguinal hernia, or the ilioinguinal nerve.
The other possibility is that the two are not related and he tingling is due to infection, dermatitis, STD or frictional injury caused by sex or masturbation.
Since a confirmed diagnosis is not possible on net, please discuss with your doctor. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.
Question - I was doing pull ups till failure over a week ago and I did feel a strain in my lower abdomen. As a result my penis has been numb and my sack not tight...unless I pee or go#2. For overa week I'm unable to maintain or get an erection...anyone ever have this issue?