I drink about half a gallon of bottled water daily. I also take two supplements that help,
GNC Mega Men's Prostate and Virility mix, and
Semenax. I've been taking them for three years or so now. I first noticed my loads getting smaller when I hit 49. I first starting taking Semenax then, and have not looked back. It really does help. I buy them in the one year supply. They recommend taking four a day, I only take two and notice it helps. Not only does it increase the amount, it also increases the intensity of the orgasm.
First year with Semenax was the most costly. After that I've been getting really nice discounts. And since I only take half the recommended amount, they last twice as long.
Not sure if it's a placebo or not, but they worked for me. My loads were getting quite little, and that's not the case anymore. Not record setters, for sure. But as good as they were when I was younger. I'm turning 53 next month, so cannot complain one bit.
One other thing, I've mentioned it before. Don't know what it is about bananas, but if I eat one about an hour or so before, OOH BABY! It does really seem to make my cock more sensitive.
Plenty of reading on the subject here.
Tease yourself as well. Get on the edge and stop. Repeatedly. When you finally do drop the load, it'll be more intense and larger.