i have to beg my boyfriend to have sex sometimes

We've only been dating for 6 months, and it already feels like he's getting bored with me. He's a full time student and also works full time 6 days a week so when I tell him it hurts my feelings that I have to ASK for sex, he said it's nothing more than him being tired. When we do have sex it's still nothing short of amazing. But still....the fact that I have to almost beg him to have sex with me just makes me feel so awful and insecure 😞