Hello,
What your boyfriend is having is erectile dysfunction and nerve problems may be responsible for this. It can also be due to injury to nerves; lack of blood supply to penis; in certain diseases like diabetes, hypertension, high cholesterol; neurological problems like parkinsonism ,multiple sclerosis; stress ,anxiety, depression; too much of alcohol ,smoking ;injury to pelvic area etc.
I suggest you should avoid alcohol and smoking if you have habit. Do sensual exercises, get counseling and eat healthy food.
I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
I would urge to go see a doctor. Maybe he just has a lower sex drive than you. However, there can be various reasons as to why he might have a low sex drive and erectile dysfunction. Is he depressed? Is he on any medication? Is something bothering him? How long as this been going on for? It could just be something psychological that is causing this. Whatever the cause may be, the first thing he would need to do is see a doctor and take it from there.