I have been having bowel/intestinal discomfort for some time now, what is wrong with me?

I'm not entirely sure how to even phrase all of this, but it seems for the last few months I have been having digestional problems. I frequently feel the need to poop, but when i do, it is usually just gas, or if anything comes out, it is usually very watery, sometimes with stuff that looks like mucus, it usually comes out in a yellowish tint. After that is out, I still feel the need to poop, like i am constipated, but no matter how hard i push, nothing comes out. It has been a few days that I have felt like this, and i'm sure it is probably just something like constipation, but after reading things up on colon cancer, I'm kinda paranoid right now :/. In the last 3 weeks my body has kind of been thrown into a whirl, my brother was in a bad car accident, my dog went missing, bills are piling up, so i don't know if stress could be a factor as well. It keeps me from sleeping, due to the frequent bathroom visits (atleast one every other hour), and i just totally feel exhausted. I also sometimes have a tough time with temperature, jumping from hot to cold, but that is rare. Some facts about me are i am a 19yr old male, 6'1, 260, i don't drink, and i recreationally smoke marijuana(rarely), no cigarettes. I don't have med insurance so I can't afford a visit to a doctor unless it is absolutely required, so if there is ANYTHING that anyone could tell me about this, if it happened to you before,anything you could suggest, etc., please respond to this.