First I want to say how you and your husband got together is a wonderful and special thing. I'll try my best to help. The truth? Just about any man, if he's with a "ready" parnter and if he cares enough about the one he's with can give their signifigant other an orgasm. To be honest, with all the information out here on how to achieve it, there's no reason for women to have one, especially when there are so many different ways. In my opinion there are four keys to reaching orgasm together
1. Your Frame of Mind
2. His Frame of Mind
4. Getting Down
Your Frame of Mind - Basically your spouse needs to get you in the mood, and this starts before he even touches you. He needs to be romantic and do the things he did to catch your attention in the first place. Your mind has to reach that happy RELAXED state that is conducive to lustful yearning. Massage can be excellent for getting there. Oils, candles, romantic music and scents. Let him be creative. On your part, you need to see him as "sexy". What clothes does he where that turns you on? What scent? Can you bring up memories when he did something you considered sexy? Look at him twice and remember.
His Frame of Mind - The ladies might not like this one, but its true - A man needs to feel like he is king of the bed if he is going to give you orgasm. He needs that macho confidence, which will assist in him lasting longer and keeping him motivated on giving you pleasure. There are a few ways you can facilitate this. One of them is to let him know when he looks or does something sexy when you are not actually about to make love. He will remember this later on when it is time to do it, and he will have the motivation to stay "sexy" in your mind. You understand what I'm getting at?
Foreplay - He needs to know your body intimately. Everyone has different pleasure areas, and what turns you on, your erogoenous zones are different from everyone else, he needs to know them. Matter of fact, he should know them and know how to pleasure you without, to be blunt, putting it in. He needs to know how much pressure to put in certain areas, whether you like to be touched lightly, licked or sucked. He can learn this without you directly telling him, if he listens to your breath and your moans. If you really like something tell him that. He will remember and keep on doing it. I'm not going in detail here since the fun of orgasm is the unique way in which each of us gets there, but this is probably the single most important physical thing he can do for you to achieve nirvana.
Getting Down - Best thing I can tell you here is if you start off moving slow, I mean really slow..., you can learn a lot about each others...areas. It is an adventure, he needs to explore..and not rush until you are ready to be rushed. I believe the G-Spot is in the upper inner wall above the vagina "entrance". He needs to practice his aim
The bottom line - If he cares for you and he feels confident and sexy himself, he will find a way to make you happy. Over time you may even start to see your body and behavior change as your sexual side becomes heightened. But after saying all this, don't berate him for not doing it for you in the past, but see him as a willing partner in this mysterious, exciting, and mindknumbing adventure of physical intimacy.
Also, you said he can only list three minutes? Tell him to practice stopping his pee when he urinates. This will build his Kegel muscles. Also, he needs to build his stomach/pelvic muscles so he won't get tired from thrusting. Enjoy.