My partner lost his erection 😞

So me and my partner usually have a great sex life but we hadn’t done it for a couple days, so last night he was rather tired but knew I wanted to BD so we started having sex. Towards the end I could tell he wasn’t into it anymore and suddenly he’s gone soft on me! What’s wrong with me? It’s never happened before!! Is he not attracted to me anymore? I don’t understand 😞😞 he said he was just tired and I know he’s been working loads (he’s a builder and is up from 5.45am and doesn’t get home till 19.00pm every night) but I can’t help but feel he’s not into me anymore! Someone tell me this is normal and happens sometimes!?