You CANNOT get PTSD from Infidelity. If you did, it would be certainly a very rare and incredible case given the definition of PTSD: "PTSD develops after a terrifying ordeal that involved physical harm or the threat of physical harm." Im so sick of people claiming they have it! When you've been in combat and routinely woken up while you sleep on the ground in the middle of Afghanistan by rocket propelled grenades and mortars landing all around you, Ill gladly help you through your PTSD... Until then, I think it just adds to your post, which seems incredibly negative and over-dramatic. You cannot obtain PTSD because your partner has it or any other ridiculous reason that Ive heard many people claim. Yes, there are likely some similar symptoms that you may experience as a result of infidelity.
My BS, LonelyHusband, served as a sniper with the British Army 20 years ago. He saw combat in Ireland, Eastern Europe, the middle east. He saw many awful things and the experience scarred him. Months of waking up screaming in the night, flashbacks, uncontrollable emotional swings and crippling triggers. Profound weight loss and lethargy. Uncontrollable shaking.
The very same things that happened to him when he caught me having an affair with a mutual 'friend'.
He has stated many times that my affair two years ago was the most traumatic event of his life, and the second time he has been traumatised by stress. He's now been professionally diagnosed with PTSD twice in his life, and says he recognised exactly what was happening the second time but could do nothing to stop it.
He has said, and I quote, "experiencing combat and experiencing infidelity share one truth. You have to believe the shocks will end sometime or you'd go insane. Until then you just do the best you can."
I'd ask you to be careful about sweeping statements. The trauma of infidelity is very real indeed. MY BS is not the only combat veteran on this forum either. Such people tend to gravitate towards each other and he has chatted with US marines, a Ranger and army infantry on here who all describe the pain the same way.