I am lost [Bambino and Breville BCG400SIL]

Espresso folks - I need some help. Curious if anyone else has my same set up and can advise.

Breville Bambino and Breville BCG400SIL.

No matter what I do and how much I try to dial in, my espresso tastes horrible. Sour and bitter. I’ve tried different grind sizes, beans, getting the 1:2 ratio, perfect brew time, tamping, etc. My family has the fancy touchscreen Breville and I have no problem operating that, granted it’s a bit easier and user friendly.

At this point, I am wondering if my grinder or machine is broken.