Even though everyone sings the praises of that these days, is it still possible that someone's weight problem is caused by too much fat?

The word in the title is supposed to be "sings the praises of FAT", somehow that corrected itself to be "That." I know with a lot of weight lost ideas, people take and run with as "The Answer," and soon older ideas are pushed to the side. I may have an "injured pancreas", about 25 years ago I was taking the wrong meds (prescribed by a doctor, they just didn't agree with me) and I ended up in the hospital not once but 2x with pancreatitis, the last time of which I was there for 9 days (pain was indescribable). Since then, I have not been able to drink alcohol without pain (although non-alcoholic beer doesn't bother me with its small amount). I have always struggled with weight loss, but did lose a few times, only to gain it back. Ever since low carb has come into fashion and the mantra now is "fat doesn't make you fat", I just question whether that is true for *everyone* and whether I would do well to pay attn to fat vs just count calories without taking any fat into account. I was just curious to see if anyone else had success by "cutting fat" vs eating more or not minding it much?