Hi there!
I have recently took GMAT for the second time and scored the same as you 595 (82Q | 83V | 73 DI).
I thought that key reason for my low score was DI section, but seeing your score analysis made me wonder whether questions you get wrong really matters. Don't have idea on that.
Regarding the
TTP - it has very good DI section, compared to other resources out there. It helped me score 82-85 on Mocks. in DI, but for some reason the real exam's DI section was much more difficult than practice questions I had. It had non-trivial graphs (bunch of dices illustrated), and very mixed up MSR questions that were hard to understand.
I would suggest you try
TTP trial to see whether it suits your needs, I used the whole course to brush up my verbal and quant and managed to improve in these sections heavily, but as you can tell DI seems to be a difficult battle.
Good luck!