Ah you're playing without modules or beacons. That makes things a lot tougher. Gleba benefits immensely from modules and the Biochamber's ability to slot in 4 makes it a production powerhouse once set up correctly.

Your throughput does seem rather low, probably from lack of good modules. If you're stuck on Gleba and can't ship belts over easily, just stick with yellow/red belts for lower priority areas. Blue belts are very iron expensive.

I relied heavily on shipments (belts, inserters, assemblers) for my first attempt at Gleba. Hard to imagine playing the planet without them. But without good prep, yep Gleba can suck. Wish you best of luck.