Urgent: Gut issues, need advice ASAP

Hey there, everyone. I’m reaching out because I’m dealing with a pretty serious health issue right now, and I could really use some advice on how to handle this. Here is what's been going on:
For over a year now, I've been struggling with pain and discomfort in my lower abdomen, specifically on the right side. Some days it's manageable, but other times it gets incredibly intense. It’s always accompanied by these alternating bouts of constipation and diarrhea. When I'm constipated, the pain honestly becomes almost unbearable. I frequently have to use warm water enemas just to get any kind of relief, and once that happens, it immediately turns into diarrhea. Almost every single night, I deal with these awful intestinal cramps and desperate attempts to go to the bathroom. It seems like lying down makes the pain worse, while standing up helps settle it a bit, and I end up waking up several times a night like this. Over the last two months, I've also started feeling this constant bloating on my right side that doesn't go away even after I've used the bathroom. Lately, I've been feeling pain in my lower back during bowel movements too. Sometimes, the stool comes out very thin, almost pencil-thin. I am extremely scared, though, because I've read that some of these symptoms can be signs of colon cancer. To make matters worse, I have a genetic predisposition; both my grandfather and my uncle dealt with colon cancer and had to undergo surgery for it. Just to give some context, I'm only 28 years old, I don't smoke, I rarely drink, and I've always been pretty active with sports. I would be so grateful if anyone knows what this might be or what I should do next. My doctors have suggested a colonoscopy, but I am terrified—both of the procedure itself, which I've heard is incredibly painful, and of whatever news they might deliver. Please, if you have any advice or similar experiences, help me out.

First off, I’d strongly advise you to stop self-diagnosing via Google. If we could all just identify our own ailments online, medical school wouldn't need to exist. You need to see a doctor immediately to get a referral for a gastroenterologist. They will determine which tests are necessary. Given your symptoms and family history, a colonoscopy is likely required. If that's the case, you can request it under general anesthesia; just ask the hospital staff about their sedation options.
It wouldn't hurt to start with basic blood work and a stool sample to check for occult blood. There are specific blood tests you can run before a colonoscopy to help determine if more invasive procedures are actually warranted.
A few more questions: What do you do for a living? Do you exercise? What is your diet like—are you getting enough fluids and vegetables? Also, did these symptoms flare up during periods of high stress?
In any case, go see a gastroenterologist and don't let fear stop you. At the initial consultation, they won't perform any invasive procedures; they'll simply take your medical history and potentially order some lab work.

So, I work at this construction manufacturing plant—basically, my day consists of lugging heavy bags around all day long. On top of the physical grind, the dust levels are absolutely insane; it’s honestly pretty unbearable. As for my diet, I’ve been eating like I actually hate myself for years now. It's mostly just dry, processed stuff, and I lean way too heavily on deli meats and jerky. I barely touch any fruits or veggies. My meal timing is a total mess, too; I skip meals constantly, then eat whenever I can get to it, which usually means a big meal late at night after everything's quiet. I definitely consume way too much caffeine to keep going. And man, the stress... don't even get me started. The last two years of my life have been nothing but absolute chaos.

Does anyone else have any other suggestions? Thanks in advance!

Get to a doctor immediately.