If you indeed found a block now, you should know there is no subsidy for any block from 8000 to 8499 i.e. the reward is 0. What you are earning are essentially transaction fees, so it is probable that the block you found might not have had any transaction fees either. This all should change once we hit block 8500, when you should see the expected reward based on the formula described in the OP.

I understand this is frustrating for you, but this is where we are. We should reach block 8500 in a day from now give or take.