You say that he becomes hot to trot as soon as you bring up a sexual discussion. You are going to need to be firm with him, no matter how 'firm' he becomes and not allow the discussion to turn into another disappointing sexual encounter. You need to insist that you need to talk about your sex life. Lead with loving, positive statements like what you told me (that he is wonderful, that you love him and your life with him, etc. ) I wouldn't tell him that you couldn't imagine life without him, which will lead him to believe that you will never leave him even if he doesn't improve his technique. Such a message would give him too much power and too little incentive to change.
Then get down to brass tacks. Tell him that you know how much he wants to please you sexually, but that every man needs to become an expert in his particular lover's body and sexual response. Tell him that you want to show him the spots and type of stimulation that turn you on. Tell him that you are going to need to have practice sessions in which he focuses just on you and learning about your body. During these sessions, intercourse is not on the menu. Have him ejaculate before you begin the session, so he isn't chomping at the bit for intercourse. During the sessions, guide his hand and mouth, encourage what feels good with words and sounds. Rewards his efforts to learn about you so that he will want to take another lesson.
Once he learns how to please you, you will be ready to add intercourse back into the mix. When you do begin having intercourse, make sure that you don't allow him to enter you until you have had your orgasm. As for his ejaculating too quickly, tell him that many men haven't learned how to recognize their premonitory sensations (the sensations just before the point of no return). Once a man identifies these sensations, he can learn how to delay orgasm almost indefinately.
Search my archives and you will find a full description of the two techniques that are used to teach a man to delay his climax. These are called the stop-start technique and the squeeze technique (both manual techniques). You need to have practice sessions with him in which you teach him to recognize these sensations so that he can learn how to delay his orgasm. During these sessions, intercourse is also off the menu. Once he knows how to delay during your practice sensations, he can resume intercourse with you; when he does, he will know how to use these techniques himself in order to delay his orgasm during intercourse. After you have practiced a while, your sex life should perk up. Let me know how you do.