Life altering, earth shattering bowel movements

Dude i know i MIGHT wanna go to a doctor with this but i'm pretty busy and just need some advice badly😭🙏🏻 I've has bowel movements every day, even down to the exact hour, before about 3 months ago. Recently, however I've been going up to a week without one. Thing is i eat lots of fiber in my diet, get an ok amount of exercise and drink about a liter of water every day. When I do get a bowel movements nowadays it literally feels like i'm giving birth. I'm not kidding that's how bad the cramps are. Has anybody dealt with this? Any Shitting Advice™?