TMI/ poop warning

Hi! So I can't get healthy poops. For the past few months (4+) my poops were just liquid, happening several times a day and often yellow/ light brown or even green in color. In the past two weeks I've started taking fiber powder every morning and a multi vitamin and increasing my organic fiber content but it hasn't gotten me back to normal hard poops. Normally I wouldn't be too concerned about this, but my boyfriend wants to try butt stuff and that is NOT happening until I no longer feel like I may poop on him.

In a typical day I eat:

Breakfast: 20 oz home made chai latte with fiber powder, whole wheat avocado toast/ pb toast/ scone on treat days, etc. something bread based mostly

Lunch: whole wheat grilled chicken and spinach sandwich (home made, I pack a lunch), applesauce

Snack (optional): (home made) honey roasted peanuts/ nature valley/ kind bar

Dinner: normally whatever my boyfriend makes. Mac and cheese, hamburgers, chicken sausages, pizza, etc

On the weekends I eat whatever I want. I don't drink excessive amounts of alcohol. After my morning tea I drink almost exclusively water. I don't drink anything carbonated as it upsets my stomach.

Any suggestions would be appreciated! I'm a university student so I have a tight budget and need to be able to meal prep. Thanks!