You are asking a lot of questions that none of us are going to be able to answer...you will have to ask your BF. His reasons could be any of a number of things. The BEST question at this point may be for you to ask YOURSELF--how important is sex to me and do I love this man enough to live without it.
When I met my H, I was 25 and virtually inexperienced with sex but an eager pupil. My H is 13 years older than I am, but right out of the starting gate in our relationship, he indicated that I was too eager and wanted too much. I understood that to mean that HE decided when we would have sex.
Yes, my H initiated since he was in control of the frequency. In addition to his low libido, he also experienced premature ejaculation, so I almost never gave him oral or touched his equipment...he couldn't take it. We usually had very simple direct missionary position sex. He always made sure that I climaxed and he used oral to make that happen in the most expedient way possible...much like pouring kerosene on the fire. Git er done...then go to sleep. This type of sex happened in the early years of our marriage on a once or twice per month schedule. It was impersonal and often the only "special" attention I received from him.
Was porn THE major contributor to our sexual problems--sure it was *a* big factor in my opinion. But so was smoking, workaholism, emotional immaturity and neglect, lack of communication and DAM-ness. Most of it garden variety chit. But enough about me.
What do you want to do since you care about this man? According to your sig, you are 42 years old. Even with my experiences with the porn thing, I can't identify a whole lot with the concerns you have expressed about BF. You love a guy who has some seriously disfunctional attitudes or insecurities about sexuality and it doesn't sound like he views it as a problem...am I right? If he does come to a place where he admits he has some issues here, will he get therapy and do the work on himself to get better? How will you feel if he won't? What boundaries are you willing to set to protect yourself?
Sounds like there is enough concern on your part about this, that the two of you need to knuckle down and discuss. Don't be afraid to do it and sincerely express how his behavior is making you feel. You will learn quickly whether he loves you enough for you to be making this level of sacrifice.