Cyclist's Syndrome or External Iliac Artery Endofibrosis: This condition is characterized by pain in the groin area, numbness, and weakness in the legs, which can be exacerbated by physical activity such as cycling or intense workouts. The patient's symptoms of pain in the inner thighs, numb sensation in the penis, and weak urine stream could be related to compression or damage to nerves and blood vessels in the pelvic area, which is common in cyclists or individuals who engage in activities that put repetitive stress on the groin area.

Piriformis Syndrome: This condition involves the piriformis muscle compressing the sciatic nerve, leading to pain, numbness, and tingling in the buttocks and legs. While it primarily affects the sciatic nerve, variations in anatomy could lead to symptoms in the groin area.
Lumbar Disc Herniation: A herniated disc in the lower back can cause nerve compression, leading to pain, numbness, and weakness in various parts of the lower body, including the groin area and legs.
Peripheral Artery Disease (PAD): Although less common in a 30-year-old, PAD could lead to diminished blood flow to the legs, causing pain during exercise and potentially numbness or weakness.

Testicular Cancer: While rare, testicular cancer can present with a variety of symptoms including pain, numbness, or a feeling of heaviness in the scrotum. Given the patient's age and symptoms of numb sensation in the penis, it's crucial to rule out testicular cancer.
Spinal Cord Injury or Compression: Any condition that compresses or injures the spinal cord can lead to a wide range of neurological symptoms, including numbness, weakness, and bladder or bowel dysfunction.
Aortic Aneurysm or Dissection: Although extremely rare in a 30-year-old without significant risk factors, an aortic aneurysm or dissection can present with severe back or abdominal pain and is a medical emergency.

Meralgia Paresthetica: A condition characterized by numbness, tingling, and burning pain in the outer part of the thigh, caused by compression of the lateral femoral cutaneous nerve. While it could potentially cause some of the symptoms described, it's less likely given the specific location and nature of the patient's complaints.
Fabry Disease: A genetic disorder that can cause a variety of symptoms including pain in the hands and feet, but also potentially in other areas due to small vessel disease. It's rare and would be an unusual diagnosis without other supporting symptoms or family history.