Problem with multiple orgasms - help!

Hey,
I'm on a path towards trying to become orgasmic. I have worked my PC muscles to the point where I can now fully hold back ejaculation. I am at a point where I can do this with ease, but when I do i still lose my erection. I know that this means that the semen went to my bladder and will be harmlessly release the next time I urinate, but how do I fix this?

There was a time where I was able to hold back without losing an erection for atleast 2 or 3 times, but now I can't do it. Am I flexing at the wrong time?

Thanks in advance for the answers.