Hello,
I suggest you don't worry too much about his sexuality which might be showing some bisexual tendencies which are shared by many. If his committment is strong he is unlikely to act on these.
Whatever the reason for his fascination (or addiction) with porn of any sort I suggest you worry about that as porn can be dangerous and damaging to certain types of personality and over-exposure to porn is not recommended to any sort of personality.
Certainly his porn watching cannot be claimed to be private while he is part of a couple and that he claims it to be so tends to prove he is already damaged by it or he is still too immature to know what a committed relationship actually is.
One of the most important rules of a relationship is never saying anything not true or meant even under duress. As he said he doesn't love you I suggest you assume he doesn't and make your plans accordingly.
If you are still quite young and do not have much invested in this relationship it might be much simpler to pack his stuff than trying to work through and save it which could be a long and complicated process if his "addiction" is severe.
Good luck!