WORRIED SO MUCH IT’S DRIVING ME CRAZY!

Hi everybody. 
 

I hope everybody is doing well and I'm sorry to bother you but I constantly worry.

 

ive been to the doctor but without checking properly they always put every problem I have down to anxiety. 
 

ive been feeling generally unwell for the last couple of months, but have started having other symptoms like pain in the rectum, pain in my left side of my stomach and pelvis, excessive flatulence, bloating and a change in how my stools look. I haven't seen any blood in my stool but sometimes it is darker and I haven't lost weight.  
 

I've had Blood tests that came back fine and the doctor has pressed around my stomach and he said it feels fine too. Does anybody know of anything else this might be or does it sound like bowel or another cancer, or something completely different please? 
 

Thanks in advance for all your replies and I hope your all doing well and keeping safe. 
 

god bless you all.