LB7 Coolant in the Oil HELP!

[dgalvin66]

So I finally did the pressure test today.
Pumped to 15 psi and it dropped by 4 psi in 10 - 15 minutes.
Could not hear any air leaking from the oil filter mount but the wind did start blowing slightly while we were out there. We did not see anything leaking.
The oil is milky and it's hard to tell if there is any oil in the coolant.
It has never blown any smoke or any loss of power.
After running the upper hose was never hard later on or following morning.
The hose has never been collapsed.

What should I check next to determine if it is the Oil Cooler or something else?
I am disabled and have a friend come over and help me to do this stuff since I can no longer do them.
I am also on a fixed income with nothing to spare so I need to be sure of problem before spending money on a repair.
If this turns out to be HG the truck is gone because there is no way I can swing that repair.
Thanks

[dgalvin66]

UPDATE
I have done several tests.
I put a glove on the radiator tank and ran the engine and it never inflated.
I checked the coolant for any gasses and there was none. These 2 tests tell me it is not a head gasket.
I did a lot more reading and research and decided it must be the water pump, I started that project yesterday and thought that I had finished today but found a large leak. It looks like I must have nicked the O-ring at the top of the bypass tube. I ordered new O-rings and will fix that next weekend,
Then I changed the water pump and removed the bypass tube I found black silicone around the top of it at the upper O-ring, so I am guessing that the shop that did the water pump years ago had a leak and did not say anything.
Has anyone used silicone at this location?

Now here is a real kick in the pants about this entire ordeal.
This all started because the coolant level dropped by over 1/2 a gallons twice and when I checked the oil the dipstick looked like milkshake on the entire length and to me it looked like the level was over full.
I drained the oil pan and there was NO coolant in it, only 2.5 gallons of very black oil.
I never noticed any type of coolant leaking, only what I believed to be the AC condensation.

I may have replaced the water pump for no reason, I did not look at the old pump to see if there were any sings of leaking at the weep hole yet.