Not eating enough

Anyone else struggling to get enough calories in them after starting ? I'm om 3rd week of Tirz compound and I'm struggling to eat which of course makes me feel tires. I've got every protein shake flavor imaginable but I'm averaging 800-1,000 calories a day and not enough protein. Also if I eat a decently portioned meal the acid reflux is intense ! Down 5 lbs in first two weeks I'll know more next Tuesday how the 3rd has done for me.

Has anyone else experienced this? Or similarly? What helped ??