Please just stop.

Okay ladies, don't get me wrong having long lasting sex is amazing, but there is such a thing as lasting too long. My boyfriend and I have been having sex for over 6 months and a majority of the time he takes to long to finish or just doesn't at all. I'm already done and satisfied and for some reason nothing I can do can make him ejaculate. He says he's fine and everything is normal when masterbating but when we get busy, nothing. We've seen a doctor and had tests done and the doctor thinks it isn't a physical problem but that it is a psychological problem. They recomended he take multi vitamins and maybe if possible he talk to a professional. He doesn't feel comfortable talking to someone about it but he does take his vitamins. Can anyone relate and/or have advice?