One other thing to consider is subconscious disassociation. Men often learn or teach themselves to disassociate as a way of controlling the timing of their orgasm, and sometimes this becomes pretty automatic. If you have a caring partner, talk it over with them. Ask if they would mind if you were totally selfish just once, for discovery purposes. If they agree, then concentrate solely on achieving that orgasm, even if it's premature, instead of trying to drag it out. If it works, then go from there. There are physical ways of controlling orgasm such as dipping a foot into warm water to achieve one, or cold water to put one off. Might be a little awkward, but probably worth it.