we live together, but various commitments mean that sometimes we don't really 'see' each other for a day or two (i.e. I leave before he gets out of bed and he gets home after I've gone to bed) but if we've had a hectic week or two then we'll make sure we spend some quality time together at the weekend, we also have a couple of hobbies we share so that helps to spend more time together
I'm 23 and we've been together around 4 years
if you're not happy then talk to your partner about it, it doesn't mean being clingy it just means prioritising each other and making sure the other feels important - I'm sure there is a compromise you can find