First off - sorry to hear you are having problems with the military stuff and got hurt....and also very very very sorry to see that your pup got hurt!!!!!
I have to wonder at what type of training you are being encouraged to do from your descriptions!!!!!! But I TOTALLY agree with Carmen. What you are admiring and training for is exactly what I, as a breeder, an owner, an experienced trainer, abhor about dog parks!!! Teaching a dog to lie on top of other dogs is not socializing!!!! It is aggressive and dominance! In this instance your dog was not under control, your dog was allowed and encouraged to approach and even try to dominate a strange dog...and unfortunately, he paid the price by being attacked and hurt. In most cases, it would have been your dog who actually attacked the other dog with the behavior you describe...but that would come down the road if you continue training for this type of behavior.
Dog parks are not good places IMO....things like this happen all the time...dogs get ambushed, attacked and hurt.
I would get the dog to a vet. He needs a specific course of antibiotics with punctures in the mouth...not just anything you have lying about.
Csabre Sch1, Hexe Sch2, SG Bengal, Komet, Kira HGH & Kougar v Wolfstraum ~ Ziberia BH ~ ATB Danger Sch1 RH SAR ~ Kougar Sch3, Kyra Sch3, Cito Sch2, Alice Sch1, Kelsey CD, Ret ~ Basha & Fenja Sch3s