What is the reason for the penis being difficult to erect and frequent sperm emission?

Patient's question:

26 years old
Condition: From the age of 15 to 17, I experienced morning erections every day, and at that time, I had a frequent history of masturbation. After the age of 17, I sometimes had morning erections, and sometimes did not, occasionally masturbating as well. In recent years, I have had the problem of frequent nocturnal emissions, with the most severe case being for 5 consecutive days, with emissions every day. I also experienced emissions when I was tired, after taking a cold shower, or during a nap.
Current general condition: When sleeping alone, my penis can become erect and I can complete masturbation. When having sex with my girlfriend, my penis secretes pre-ejaculate fluid, but it is very difficult to get erect. Even when it does, it is not very hard and quickly becomes soft. Sometimes it happens like this.

Doctor's answer:

The above conditions are often considered to be caused by kidney deficiency, erectile dysfunction, and other factors. Erectile dysfunction refers to the inability of the penis to achieve and maintain an erection sufficient for satisfactory sexual intercourse. The main causes include psychological factors and organic factors, such as long-term inappropriate sexual activity leading to psychological stress, inappropriate or insufficient sexual stimulation, adverse sexual experiences, poor sexual environment, abnormalities in the corpora cavernosa, endocrine diseases, and other factors. Common treatments for erectile dysfunction include psychological therapy, behavioral therapy, and targeted treatment for specific causes. It is recommended to visit our department of sexual dysfunction in the hospital promptly, follow medical advice, and undergo relevant examinations such as nocturnal penile tumescence to clarify the condition. Based on the examination results, cooperate actively with the treatment as directed by the doctor.