Reddit mentions of Fix Your Gut: The Definitive Guide to Digestive Disorders

2 weeks is way too long - I had that experience once and it was awful (but I was able to resolve it without a trip to the doctor thankfully). Miralax was the only thing that worked for me at that point. Do not develop a dependence on it, it fucked up my stomach after I took it regularly for 2 years, but it really does work better than anything else in the short term. I'm at the point where I will take a laxative if it has been more than 2 days without a BM. This is what I use at the moment for a gentle laxative to take during dinner if I've been backed up:

https://www.amazon.com/Dr-Schulzes-Intestinal-Laxative-Capsules/dp/B000X1U6EQ

But for now you need the big guns, take miralax, and glycerin suppositories (to help it not tear up your rear end on the way out). If that doesn't give you a BM in 2 days, or if you get any acute pain or vomiting - see a doctor.

Also for headaches and stomach pain, taking cannabis has been a lifesaver for me (perhaps literally).

Edit: for the future when you have time and money to devote to finding a more long-term fix for your gut health issues, I can't recommend this book highly enough:

https://www.amazon.com/Fix-Your-Gut-Definitive-Digestive/dp/1974682021

You will have to make a serious commitment to completely alter your diet though, and spend hundreds of dollars trying out diets and supplements until you find a combination that works for you.