Not sure how I missed that you had been to a doc already, oops. Didn't mean to be redundant there.
I don't want to jump to conclusions as to what you have, because it could be a number of different things. Some docs would help you go deeper into finding out the root cause of the pain if it's really bothering you every day, but it sounds like the one you went to didn't go beyond the ultrasound. If you don't wanna try another doc (they can have very different approaches btw), then I'll try my best to help.
You're young and the ultrasound showed no gallstones, so I'm 99% sure the pain isn't being caused by them. If it were me, I would look back to when the pain started showing up, and what you're currently supplementing with.
Questions that might help:
Is the pain sharp/sudden or dull/continuous, etc?
Does it happen at similar times of the day, like a few hours after eating/ingesting anything or taking supplements?
Can you think back to when the pain started showing up, and what you may have been doing differently then?
Does anything seem to make it worse, even if it's "supposed to help"?
Have you gone for long (few days or more) periods of time with hardly any/no pain? If so, what were you doing differently?
I really can't hypothesize more than that. For your question, TBH my diet did most of the heavy lifting so to speak when I was getting over acne, and continues to do so. I'm not against supplements though and I take a few basic things like Vitamin D/K, Fish Oil (bottle not capsules), Thorne Probiotics, and Magnesium occasionally. I took Berberine for a short time and it helped speed my recovery, but I found later that I could do without it, as it caused some muscle soreness I didn't want. If I had only taken Berberine, it would have been a "quick fix" type of thing, instead of a lifestyle change.
It's really essential to know your side effects and not buy into the hype with things. The more I research into supplements though, the fewer I seem to need ... works for me as it saves money ;)
So I recommend you take a look at what you're ingesting, and know the side effects for EVERYTHING. A good resource to do that is:
examine-dot-com-slash-supplements (they wouldn't let me post the link so I had to type it out, lol)
Hope this long-winded answer helps!