What's wrong with feeling lonely? Just because you feel lonely, there isn't any obligation to let loneliness cause you pain. As someone whose job is porn I have a bias, but I also have a lot of experience with the relationship between porn and loneliness.
When I went away to college, I didn't make any friends, so I was lonely most of the time. During this time I would spend a lot of time searching for tricks and medications (self-prescribed usually) to alleviate this suffering, because I hated to feel lonely. I think I may have even made one or two posts similar to yours. It was totally invisible to me that this pain was self-inflicted. I genuinely thought that the cause of my pain was from being alone, and not from my response.
My thoughts became sadistic. I shamed myself for being alone because I felt bad not being in a relationship, because I felt that if I were in a relationship, I would be satisfied. I shamed myself for masturbating to porn because I was conditioned to thinking it was "unwholesome". I had no love for these parts of myself.
The cause of suffering is craving, it's when you want things to be different from how they are. If you are lonely but you don't want to feel lonely, you will suffer. You may feel you are craving a relationship, but what I think you are really craving is to not feel lonely (which in your imagination looks like a relationship), so you suffer. The reason someone can meditate in caves in seclusion, despite being human and feeling a need for social connection, is because they love the lonely parts of themselves as well.
When I viewed porn in and of itself without trying to shame myself due to my societal conditioning, I realized I actually loved it, that it was a positive part of my life, and even a powerful reminder to how silly the mind can be. Why would I quit something that brings me happiness without harming others? Well, I actually did quit porn once, but when I did, I was just as dissatisfied as I was before, because of course, life is unsatisfactory. So I went back to it but having realized the pointlessness decided not to feel guilty or to shame myself, and from that point on I was free from that toxic loop.