Few things (firstly obviously, why is she your girlfriend again? Usually some kind of sexual attraction is a prerequisite to relationships...):
I used Viagra to get erections, and after a while I realised that's because her body won't turn me on.
This seems like a strange thing to "realise"... did you experience erectile dysfunction prior to this relationship, which lead you to start using Viagra? It's also possible that you have an underlying health condition that has nothing to do with her - in fact I'd say it's more likely. I mean... how do you end up in an apparently kind of sexual relationship with someone who does nothing for you...? It's always easier to find external reasons for our problems.
I always have to make the initiative. This means I'm horny enough maybe once a month.
It's pretty normal for one partner to take the initiative more often. Is this something you've ever talked about? If not, you should. If she's unwilling to look into her own reasons for having a low sex drive then yes you might just be incompatible. HOWEVER, once a month to me suggests a pretty low sex drive from you also, depending on age... which makes me think it's even more likely that you yourself are not in the best of health and should probably try to address this first. If both of you are neglecting yourselves and experiencing suppressed sex drives for this reason, I'd say you should both independently try to work on yourselves before blaming the relationship for your own issues. I mean... maybe your girlfriend is in fact a sexual person but is just being kind to you about the fact that she never wants to have sex because she's not attracted to you. But there has to be some reason you both ended up in this relationship..
I'd probably want sex more often if she had a hot body.
I would not count on this.
This results in me having to watch porn and masturbate sometimes. It's kind of lame having to masturbate while having a relationship.
Hmm, you said that you're horny enough to have sex maybe once a month. How often are you watching porn and/or masturbating?
It's not unusual to masturbate while in a relationship - it's not your partner's job to ensure you never need to masturbate. The fact that you think it's lame to have to makes me think your expectations about relationships are pretty skewed, and overuse of porn is pretty well documented by now to really fuck with one's expectations about sex and relationships.
It's quite possible that you are both just incompatible, but there are several things about your own habits and your own mindset that should concern you, and you should be focused on before you start thinking that having a different partner would just fix you, because I guarantee it won't, and unless (or tbh.. even if) you're only with your partner out of convenience and insecurity which prevents you from being with someone that you actually want to be with then breaking up with them isn't going to immediately resolve whatever issues lead you to this situation in the first place - if anything it will make it worse.
To be honest it doesn't sound like you are in the right place to be in a relationship, although not for the reasons you think - but before you go throwing the baby of a relationship with a hopefully good human being who hopefully genuinely cares about you, out with the bathwater of your own insecurities, skewed expectations, and unwillingness to deal with your own physical and/or psychological issues... I would just take a closer look at that bathwater.
I am Blind so I don’t know exactly how looks/Body type determine sexual attraction, though I guess it’s analogous to how voice, Personality and behaviour determine whether I find a girl sexually attractive or not.
Moreso just voice, out of the things you mentioned. Although IMO, voice and personality - and behaviour, which can be grouped with personality, really - should not be grouped together, for the same reason I am about to explain. What someone
looks like, just like what someone
sounds like, is a surface level trait anchored solely in one of the primary human senses (sight, obviously) - but personality is far more complex, and generally takes precedence over the shallow, first impression properties of what someone looks like, and what someone sounds like... And given enough time to experience someone's personality, can even alter the way we think about this more basic sense data.