Did you ever find out what was wrong with you? I'm having almost the exact same symptoms, and I'm wondering if I need to see a doctor.
You need to see a Gastroenterologist to determine what the problem is. It sounds like maybe you have something like Ulcerative Colitis, but that can't be said for sure until you see the appropriate medical professional. I know it may be scary to experience these things, but the reality of the situation is that you will never know and constantly wonder and have that burden on your shoulders, not to mention the fact that not seeing a doctor is just not wise when you are experiecing the symptoms that you are. Ask your PCP for a referral to a good GI doctor and get this problem diagnosed and treated so it doesn't get worse. & yes, I would be worried if you do not see a doctor becuase it seems as if a condition is developing as time goes on and whatever it may be, goes untreated.
I am not saying this to be mean or to scare you, I'm just being bold and being truthful with you. My mother died of cancer at the age of 40 and it could have been avoided if she addressed the problem right away. She kept putting it off until it was too late. So, when someone puts things off and hesitates getting treatment, it gets under my skin because doctors will help you, not hurt. Please see a GI doctor ASAP.
I can tell you this. Even tho your last waste was not hardish, then if the one or two previous were, it can bleed like that for a couple days. This is because hemorrhoids are delicate vascular tissue that has swollen up, so if anything really pushes hard on it, it just rips open and bleeds. It's like getting a bad cut on your fingers, you use them all the time, so it tends to swell and take a while to get better.
Good you're keeping up with fiber, but water is key to keeping waste from getting hard. Everybody's does from time to time, depending on what they ate, any medicines they take, vitamins will sometimes stop up a person, lots of variables, but water is the great equalizer when it comes to digestion. They recommend a rather large amount, 8 glasses, but you wind up peeing all day long. So, shoot for 6 glasses, keep a cup in the bathroom and every time you're in there, guzzle down a whole cup.
To stop the endless irritation on your rear, which exacerbates the bleeding, get some plain KY jelly (not the flavored kinds) and put it on after every time you bathe. This is a non-greasy water-soluble jell. You can reapply as needed. I will use a damp tissue for a final wipe, to get all the junk off there that irritates it, and reapply the jell. This is just for when you have this going on and things chaffe too much.
As for what ELSE it might be, if those steps don't work (water & KY), I think cancer is a remote possibility, but another scenario is you can get these little bowel pockets that form from too-hard stool being in there, and once in a great while they can get out of hand and become abscessed, so you'll get extended bleeding. Or could be at some point you actually tore your SKIN, not the hemorrhoid so much, and you have a fissure, and those are tough to heal, and lots of people get them, a real pain for sure.
But I will agree with you, I think you should be concerned of the blood being dark and red, and this suggests a blood clot, but since you had some bleeding for three days, could be some was still at whatever place is torn or infected or whatever, and it finally came loose as a clot. I don't know for sure. Hope your doc visit is soon, no need to be worrying about all this jazz at your age, altho if it's any comfort, ANYTIME a person has digestive issues, it is an overwhelming sort of thing to happen to a person while it's going on, and this is partly described by the term "the human condition."