Mm there are and have been many terms to describe what sounds like your situation. Some of these terms include "libidoist asexual", "aegosexual" and "autochorissexual". While they might not necessarily be the most used terminology, their existence proves that this matter has often been thought about in ace communities over the years.

I then just felt like including another person added nothing to it for me

I feel like there are a lot of ace people who can see themselves in this statement. Think about whether you feel sexual attraction... Not if seeing something like porn makes you body aroused, that can happen to an asexual too. But if you truly think about a partner: I have a desire to have sex with them, I am sexually attracted.

Most asexuals or at least, asexuals who hang around in the communities, indeed have lower libidos and even lower interest in sex of course which can make it seem like you wouldn't fit in but... masturbation is something that is quite personal so just because someone doesn't talk about it, doesn't mean they're completely removed from it. Aces tend to bond more over the "I don't want to include another person". (And even then it's not descriptive of everyone). I think it's important to accept that all aces have a bit of a different experience about sexuality. My idea is that asexual people do, in fact, have sexuality, it's just sexuality that is oriented in the asexual way. Someone else might (and certainly does) disagree with me on that.