<human>: Boyfriend and I have had a pretty solid sexual relationship, having usually had sex daily only because he has trouble going more than once a day. Out of the blue it seems he has had no sex drive and after the first couple days he brought it up just saying he was sorry and noticed without giving any real reason. He doesn't seem particularly stressed and our relationship has been great otherwise. We've been dating for about 6 months now with the only gaps being heavy periods but honestly I've been trying so hard and getting nothing in return and I'm so frustrated right now. I would never cheat but I'm just starting to wonder if this is going ro be a problem....I tried "not trying" for a few weeks
 but this just results in him wanting blowjobs. I'm starting to feel incredibly self concious and unsexy to him...... Any tips or advice for a young sexually active female? Little background: I regularly masterbate but get very little out of it as I mostly crave intimacy, he masterbate when we don't have sex and has been which I'm comfortable with but I don't think he has been lately.....is it more likely outside stress or relationship stress? I've tried bringing it up but he always has an excuse like "my stomach hurts" or I'm really tired" or "can i please have a bj".

Could you distill the essence of the text into 1-3 sentences?
<bot>: my bf hasn't wanted sex in over 3 weeks and I don't know how to appropriately and sensetively respond and cope.