i'll place all assumptions ... i apologize if it offends you. my words may be very straight forward

some ppl have different level of understanding .. so ....
i assumed that you might be misunderstood on the your body fluids .....
Cum and Ejeculation is different - cum comes first (as lubricant) then Ejeculation comes later
if this answers you .... that you've misunderstood, so basically maybe you lack of endurance to continue, so jog more, exercise more .. build up ur endurance
here's where you can identify which is Cum, which is Ejeculation .... so .. basically you have a problem ....
drug only works temporary ....... but for you, for me, for everyone else .... we want permanent solution ......
so ... basically PRACTISE MAKES PERFECT .... your body will improve with practise ...
but keep in mind, this can happen to everyone NOT ONLY YOU ......
Although everyone of us is born to run, but very actually run the BEST. WHY? coz they TRAINED themselves ... similiarly to your problem ... we may by instinct of such a thing, but we are not born BEST, so CHIN-UP, don't feel depressed, and practise hard
this is extra ...
to help you exercise the internal part of your muscles to be extra tough .. so it'll give OT (unpaid ones)
it's quite simple .... there's 2 ways

first method - play with your urine (no joke)
remember when you're a kid when you played with your urine? every kid does it ... urine half way, then hold the urine (it hurts right?)
1st stage
drink a lot of water, go to the toilet, and urine, hold it for 5-10 seconds and release ... do repetitions
for some ppl ... doing it may be painful ... but do it regardless ... do it until you can hold it for more than 5 mins
this stage might take up to a month or two before your internal muscle actually strenghten up .... in this stage, ur problem most likely is solved

2nd stage
to further strenghten your part ... remember previously you've hold your urine?
instinctly ... you'll know which part of your muscle used to hold the urine ......
so ... you squeeze the muscle and perform it around 100 times per day ... you can do this anywhere, so 100 per day quota is pretty easy to fill in
by the time you can do 300, most probraly you already qualify for a porn star (compliment)
btw .. women can do this as well .. it helps their child birth (during/after)
the second method
this method is harder ... and quite messy the first few times
it's a very simple ... but hard to master

Sit down on the floor, and cross your legs
give DEEP breath, till it FILLS your STOMACH/BELLY with air .. your stomach will be round and hard
and then shrink your anus (at this stage most ppl can actually leak in their pants, and later abandon this method, that's why it's hard)
shrink and release it for 10 times

there are a few ways to work out ... do both
do it very quickly (1 sec per rep) ..... this will help you to release anytime you want
and do it very slowly (hold it for 30 sec and release) .... this will help you withstand long OT
increase the repetition as you improve
either one of these 2 methods will ensure that you wont be needing any adult diapers when you reach age of >80
this applies to females as well
hope this helps