Couple things could be going on - you are more excited by her and/ or she is tighter - so you ejaculate quicker. You are older and so you are aging naturally.
What can you do? More foreplay - so she is closer to orgasm. Have orgasms other ways. Or exercise.
Exercise you pc muscles. Do kegels.
When you pee - stop peeing count to 10 - start to pee again - stop count to 10 - start again - do this as often as you can.
Do penis push-ups. Flex your penis so it goes up and down. When you get good at it- put a piece of cloth over the top. Get good at that - wet the cloth so it is heavier.
1-2 minutes isn't really so bad - before you were doing really well - now you are just OK. So part of you is just going to have to get used to it.
Susan