Hi well come to HCM.
If you can retract fully when flaccid nothing is wrong with you need not worry. There
is nothing like to increase the quantity of semen. Depends how often you masturbate
if you do not masturbate for two to three days and then masturbate the quantity will
be more and if you masturbate three times a day than quantity will be less, force will
depend on quantity. There is no fix criteria for frequency of masturbation
. But too much
is always bad for any thing will disturb your all other activity in life and can give pschological changes due to continuous thinking on sex, Thanks