Contrary to what your mom and some other people believe, there are some men who do not look at pornography (and aren't gay either), there are also those who have at one time looked at pornography and have stopped and been able to not look at it again. The human soul is stronger than any sexual organ.
If he loves you, and understands how it affects you, he will make an effort. If it is that important to him, he will stop. Unless he believes that it is impossible to stop. But if a mother can lift a burning truck off her child to save him because it's important to her, he can stop looking at porn if he understands it's that important to you.
Here's the thing: relationships are never 50/50, they are 100/100. Each person gives all of themself to care for and meet the needs of the other person. Each person has boundaries which are areas where they can't give of them selves all the time or to a great extent. That is healthy and necessary. And part of loving the other people with 100%, not 50% is knowing where their boundaries are and not crossing them or asking them to.
You boundary is that you don't want him to look at porn. *you* want to be what he desires and is captivated by. Sex and sexuality seem very important and sacred to you. If he respects you and loves you (as in cares about you as a person and companion, not just an attraction) he will make this a priority, and I can tell you from experience, it is possible for him to stop and not even desire it any more. Anyone else who says different has been burned and is cycnical. That is unfortunate for them, but don't let that be the only opinion you have. There are always other options and choices and possibilities.
Talk it through with him. Let him know how important it is to you. If he seems unable or incapable, you know that you may not be his first priority.
I can say that for people who are very involved in looking at porn, it can be a difficult and intimidating thing to consider stopping. Some people may feel like it is impossible (by the way, not only guys have issues with looking at porn, there are many women who have a problem with it too). Some people don't think looking at porn is bad, but I think just by the way that you and thousands of other people are negatively affected in relationships because of it says there's something more to it than just a hobby.
Anyway, those are my thoughts to encourage you to have hope and be strong and set your boundaries.