If you've been DXed with peptic ulcer, you've been taking the wrong things—ulcers can be caused/exacerbated by meds like aspirin, ibuprofen, and naproxen. I gave myself a bad case of IBS by taking too much ibuprofen, and nearly lost half my bowel. Hopefully, you can find a gastroenterologist that will work with you to find a better treatment/cure, taking your PN into account.

Because of my IBS, I only use acetaminophen. Due to its harshness on the liver, I also take N-acetylcysteine (NAC) to reduce/negate that effect. I get tested regularly, and my liver is fine.

Some of those other meds can also cause rebound headaches. If your headaches are something else (e.g. migraine, cluster, et al), you might consider seeing a headache specialist (practice limited solely to headache/migraine—not just a run-of-the-mill neurologist). I suffered from two types of chronic headaches for years before finding a good headache guy who knew his stuff.

Doc