Lack of sex - we’re only 21 ?!

So my boyfriend and I have been together for

5 1/2 years, he’s the only guy I’ve ever been with and in the beginning we couldn’t keep our hands off of each other - like any new couple - we were down for sex any where, anytime, any day even twice a day ! Well fast forward to now, we both work I understand work can be draining he does work a pretty heavy labor job and I work a front desk job but I’m up at 4am, usually ready for bed by 9pm the latest. Well let me add that we also don’t live together so it’s not like I can just get morning sex or wake up at midnight for some d*** so that’s another strain in our sex life. Guys I’m too young to only be having sex once a month 🤦🏻‍♀️. Lately I feel like there’s just a lack of intimacy between us not just sex wise but we hardly ever hug/kiss anymore. He used to make me feel so wanted but now it feels more like we’re just two really close friends. He tells me he loves me and doesn’t want to break up but I genuinely don’t know if this is something that happens to every couple after a certain amount of time you kinda just lose that “spark” there once was in the beginning ? Or if it’s a sign i should be rethinking staying ? We both really do love each other though :( any advice or suggestions to help us get back to how we once were ??