Sex life / relationship

I’m currently 19 me and boyfriend been together for about 4.5 years now. I can honestly say my sex drive hasn’t been high since being a teenager due to stress and figuring out womenhood. We been moved in together for about a year now. And to put more context I’ve been working two jobs for the past 6 months basically funding both us . He complains how I’m not like how I used to be and always question am I even sexually satisfied. I always say the same “I’m tired “ “Just not now “ and i can’t figure out why my sex drive is declining . Like I do love him but then I find myself daydreaming about being single. Have anybody else been through this. If so what did y’all do to fix the relationship.