Clamping and Edging. Any way to lessen ejaculation, point of no return

After a good girth workout, and edging for a bit, I get to a point where I just want to ejaculate. I don’t necessarily have to, meaning I can take my hands completely off myself, and wait 10 seconds, but eventually I just give up. I feel that I could be gaining more by only ejaculating once a week, rather than once a day. The pressure gets so extreme that it’s almost too hard to stop. Is there a supplement to help drive this off, without making erections harder to achieve? I’ve heard st. Johns wort perhaps, or something else?