Ultimate difficulty is pretty tricky compared to the first two, you have to consider stats which were not as important before but become essential in ultimate, like resistances, defensive and offensive stats to.
One of the most sort after stats (for me personally anyway) is x% converted to health, keeps you alive if you raise it well.
I can’t answer your question directly, as my commando is a little different to yours (1h and shield), but I have many decent items - some perhaps you could take from my file I have attached. I have also stuck some of the legendary 2 hand guns I have found in my bag, they make a little difference.
I hope this is of some help. One thing I would say though is flame touched and temper from the demo tree make a huge DPS difference, I noticed you have not got those skills, they them out.
It was a mistake to ignore defensive abilities and resistances, spending most points into damage.
As you suggested, I reassigned them (choosed Flame Touched/Temper/Blast Shield instead of Flashbang, and defense constellations like character in you save) + used some of your gear.
The irony is that almost all gear I’ve used, was dropped during Act 2 walkthrough, when it’s not needed
So now I am in the middle of Act 3 with sporadic dies on some bosses.