I've been with my boyfriend for 1 year now and we have always had a lot of sex but for the last 2 weeks he hasn't been able to get an erection. It literally happened overnight, we had sex one day, fine no problems and the next day he couldn't get hard, and its been like that for 2 weeks now. I've found a lot of similar questions about erection problems and most peoples answer is that he no longer fancies me or that he is cheating on me but I don't see how this can be true as like I say it literally happened overnight. I have tried everything to make him hard and for a couple of hours at a time but it just doesn't work. He gets horny and wants to have sex but after ages of trying he gives up and gets upset about it. He is also to embarrassed to go to the doctors. I haven't made a big deal out of it, I make out that it doesn't bother me in the slightest, I've got a lower sex drive than him anyway so its not like I'm putting pressure on him to have sex. I've told him to just forget about it and that it will get hard when he wants to get hard but he's starting to freak out now which can't be making the situation any better. What can I do to help him?

Not sure where you read it means he is cheating, surely not on this web site.

First medical illness, even things like high blood pressure, stress from work, money issues can cause it.
Next postate issues and other more seroius issues.

Next the more he has problems, the more self conscience he gets and it will make it even worst.

Next sorry but a man may be cheating and have three girlfriends and have sex with all three every day and still be able to preform, esp if they are younger.

Next how old is he, at 50 it may be more common to have issues sometimes than at 20.

Next he needs to grow up, sorry to be frank, but men and women will have problems sexually and that effect that part of the body, So being able to talk honestly about it to a doctor, or a therapist is just being a grown up and admiting everyone needs help some times.

I think if it was cheating... he would have more... not less on an average day.

He might be able to do it once or twice a day with you... but not three times... but given the new girl stimulus he could pull off another one or two that same day.

That's from personal experience from back before I got married and at times dated more than one woman.

But also don't discount what Fr_Chuck already stated... thats likely where the real problem is.

Additionally... was anything said or done that might have upset him?

Well the fact is either he has some medical problem or he does not fancy you anymore. However, sometimes such situations occurs due to over self consciousness. This can be dealt with by giving him some time alone.

The likely answer at this point is that the more he worries about performing, the worse it is going to be for him. He needs to relax a little and stop worrying.