Baby screaming in pain

So from day one we have been back and forwards to the doctors as our baby supposedly has a milk intolerance. The doctors put her on a prescription milk and things improved and they have referred us to the dietician in December. Over the past month she has got progressively worse fighting her bottles (I thought it was just a phase) and she now absolutely screams when I give her a bottle leaving both me and her sobbing. I have tried changing the teats, adding thickener/not adding thickener (she also suffered with reflux), tried holding her different ways or putting her down, tried teething gel, I spend ages winding her before during and after her bottle. Nothing is working. I thought maybe she was over tired as she’s not a great napper but even that’s proving not to work either. I have been back and forwards to the doctors and they just keep palming us off till we see the dietician. She is clearly in pain as she absolutely screams the house down. I just don’t know what to do I can’t bare to see her like this anymore. I can feel myself getting more and more depressed about it all as I feel like a terrible mum for letting her go through this pain. 😭😭