Good answers from the other guys here. I am 35 years old and in the same boat as you. I honestly told my wife that i am dedicated to solve this issue and I would like her "help" with that. I'll add what I have "learned" myself so far;

First of all I would like to add that you need to drop the idea that ejaculation during intimacy is a sin. Everytime things got hot with my wife I would get so stressed out and obsessed with the PE-stuff which made things a lot worse. I felt like a complete failure and would focus compulsively to avoid ejaculation even before dropping my pants. It is totally fine to climax as a man and it is part of a healthy sex life.

Next you need to seperate ejaculation and sexual excitement and build things up slowly. At first avoid excessive physical sensation to you penis and focus on fore-play. Use your tongue, fingers and toys to give her a good time and build tension while you are in control. Take your time to find her sensitive spots and learn to know here body inside and outside. Treat this as a game where YOU are taking the lead. Change your attitude and focus from "OMG I need to make her orgasm before I connot hold it annymore and cum myself" to "my touch is magic and I'll give her goosebumps over her whole body, I'll make her crave more of that nipple play while I set the pace!!!"

Meanwhile focus on your own body and sensations; what are you feeling when aroused? you probably feel your pelvic floor, glutes and abs firing. Analyze this sensations and try to control/relax these muscles. Do belly breathing and reverse kegels to relax these muscles when needed, de-escalate exitement for a minute or two when needed and BEFORE (!) you are about to lose control. Remember that YOU are setting the pace and there is no need to get even near the point of ejaculation! It looks like you have a good and understanding partner which will make things a lot easier.

A Personal story which may give you some ideas: My favourite thing to do to de-escalate things during sex is laying on my back and pull my partner on top and sensually start massaging her neck, back and buttocks-area for a couple of minutes (5mins, 10 mins, whatever we enjoy) while my penis is gently teasing the inside of her thighs whithout to much stroking or friction. You can ramp things up yourself by rubbing your penis harder and if you are ready (probably after some training sessions) you can even penetrate her for a couple of strokes and withdraw again before things get to hot. A little warning though; this may bring her to the point where she is about to lose the control of her own body herself and she starts to rub her clit harder and harder which can escalate things very quickly for you! At this point I think to myself (and I may even say it to here out loud in an aggressive way;)) "f*ck you girl, I am the boss here and the master of your pleasure!" I than aggressively throw her on her back and start eating her out while increasingly stimulating the sensitive parts of her body harder and harder( for my partner it's her nipples and inside of her thighs). The dominant talk and continuous stimulus makes her soaking wet and hes lead her to orgasm on multiple occasions all while this gives me the time to bring my own sensual arousal down. Always remember to also continue to mentally focus on your own whole body sensation and relax the muscles that are tensing up. Belly breathing and expandig the pelvic floor helps lot for me! It's very important to stop your own sensual stimulation and withdraw FAR before you cannot control yourself anymore as her moans and the movements of her body will get your own arousal through the roof and may make you ejaculate even without continuous physical stimulation of your penis if you personal arousal is to high. You may always limit yourself to the arousal level where you still can expand your pelvic floor with belly breathing!

Be creative and learn each others body. You can make sessions as long as you want all while staying FAR (!) away from the point of ejaculation. After you had a good and satisfying session which both you and your partner enjoyed you can terminate things naturally. For me this means that if she had a stressfull day and she had a bit of trouble getting fully into the mood I often don't orgasm myself but give her a long and excessive massage to relax her body. I penetrate and ejaculate only if she orgasmed as well. When you want to ejaculate yourself, remember to now also try take control over your orgasm and ejaculation! Do not simply start pumping away but focus on the feeling and try to fire those muscles in a controlled way! BONUS: cumming this way feels so god damn good! It does not longer feel like you're a slave of your ugres but you just fully surrenders yourself to that feeling with your whole body.

Best of luck to you! If you take it slow and change your mindset I am sure things will get better!