I've seen a lot of boner problem questions but none exactly like this one..

My bf and I have been having sex for over a year, we are both 29.

We had sex on Friday night and Saturday morning. Last night (Saturday night) he could not stay hard during sex. We'd had a long day so I chalked it up to him being sleepy and we went to sleep.

This morning (Sunday morning) I tried giving him head and having sex with him but he still couldn't stay hard. He suggested we masturbate together, so we did. He was able to stay hard and cum from masturbating.

So I assume the problem is me, maybe he's just bored with me? We've been having sex for over a year and may he's just bored with the same few holes in different configurations? Physically I am the same as when we first started dating and he is constantly telling me how cute/sexy/beautiful he thinks I am, so I thought he was attracted to me but maybe that's starting to fade after being together for a bit?

I guess my question is why could he get hard, stay hard, and cum from masturbating but not from me giving him head or having sex with him?

Should I just end it now? Once the sex goes I don't really see the point in staying in a romantic relationship, as at that point we are essentially just friends. I love him so much but I don't want to keep him in a relationship with me if he isn't into me anymore...like I should probably set him free to find a girl that can make him cum reliably.