I carried 9 people last night to anywhere between 10-30 runs of Belial. Of those people, 6 of us got Mythic Uniques, 1 person got 2 3ga items and the other two, just got a ton of materials.
Your group composition matters. When you killed the boss, did you mind the tooltip and see that you have increased drops for a full group? Or did you just go in, and they killed it with just you two? If so, you're better off asking in Trade chat if anyone has materials and would like to have a free kill of the boss, to increase your drops as well.
Sorry to hear you're not enjoying the season. End game should be considered T3. T4 is only for those that have the right specs and enough time to grind. There is no difference between T3 and T4 other than a few more items, and more of a headache. If you can farm T3, spam T3 and enjoy it.