Aiyoh sayang, at 34 weeks memang common! A few of my mum friends had the same thing, the baby is pushing everything around, so your digestion gets messy and your back nak collapse je. Makan sikit-sikit je, frequent small meals lebih senang nak digest, and try to rest with proper pillow support for your back (maternity pillow really helps). Tapi since you're having back pain + loss of appetite together, best la you check with your doctor just to make sure everything okay, could be nothing, but 34 weeks is good time to confirm! Hang in there, you're almost there!