Sometimes when I’m having an erection problem I do this exersize.
1: sit on the side of your bed
2: try to get the best erection you possibly can
5: spread you legs out place feet firmly on floor.
6: bend at the waist about 30 degrees
8: bend again
This should fill it up to the max and you won’t lose it.
Speak softly carry a big dick, I'm mean stick!