Why is my breathold time decreasing?

Question:

i have been doing a few dives lately and found i haven’t been able to hold my breath for as long as i use to i only did a 20 ft dive wen i got to the bottom i had to surface again why calnt i hold my breath like before there was no current each dive i was a little out of breath every time what do u think the problem might be


Submitted from:

bowen, Australia