D1111 you worry to much man...
I use to worry like you, but after talking to my doctor about sti's etc put my mind at ease.
If you have covered oral and sex you are NOT going to get an STI.
Escorts are actually very clean, its their job to be clean, and they get checked regularly.

Now yes there is still always the risk of a condom breaking etc.
But this is a very tiny chance... condoms usually break due to friction. All the escorts use plenty of Lube for this reason. With a well lubed up vagina there is very little chance of a breakage.

So go ahead and enjoy yourself pal. You'll be fine.
And if you are ever worried or have a mishap go straight to your doctor.
They can give you 2 pills (antibiotics) that will kill gonorrhea/chlamydia in a single dose. Even if you dont have anything wrong with they will give them to you to give you peace of mind.

But ff you can't live with the small risk attached better off just keeping to your rub and tug massages dude.