It is so easy to just throw in our "judgement" as people from the internet who don't know you or your partner personally... My first thought was to leave something like that, but there are questions worth considering first.
Is the fact that your partner is "not finding you attractive" something he/she has said with words, or expressed, or is it something you just feel? It is important, because how you feel may not cover how your partner actually thinks and feels about you. For example - I have a married friend who is going through a rough patch with her husband, she basically thought the same as you, that the husband is not attracted to her any more as he avoids intimacy altogether. After 2-3 years it turned out the husband has ED and instead of communicating about it, he chose avoidance. Not saying it is the case for you or even remotely similar, just an example of what the thinking was, and how far that from reality ended up being.
By the sound of it, you would like this to change... Or would you be contempt continuing like this? It is important, because obviously it would be a compromise, but in that case could it ever burst and make you go resentful, overly frustrated or regretful? There is no point putting up with it and compromising your needs if it will result in having enough one day and feeling sorry for all the years wasted, pretending to be ok with it.
Don't want to sound judgemental, but I am not sure the way your partner reacts to the question is a fair one. Rather than acknowledging your feelings or you missing something, you are being lumped into "it is normal for people in our age". I don't know, it is normal for people in my age to start losing their hair, doesn't mean I would like it to happen, you know? :)
So, ask yourself the above question(s), and see where you are, you are way too young to be in an arrangement that does not fulfil your needs.. I know i don't speak for everyone, but me personally, I'd rather be alone than with the wrong person. (Disclaimer: I am not saying your partner is "bad", at all. Can still be an amazing person, great to be around, etc )