need help please.... i feel weak somehow and unable to finish that raid solo profound darkness gemini... this is what my build looks like : back and arms has the same affixes.

this is leg armor cause i dont have any more resources. so currently using it like this.

and this is my GU skill tree ( GU main )

And this is my HU sub skill tree :

i took iron will max and auto mate max because i feel crispy weak....

This is my Stat currently

This is the MAG:

this is my current ring. HP restorate because when i fought Gemini ( the solo raid one) i feel sooo weak and dying a lot

and after all this still unable to complete that one solo raid Gemini cause always running out of health potions........ where did i go wrong? any advise? please help

Your build basically has no room for major improvement; the only advice I can give you is a quote from DBZ Abridged's Piccolo: "DODGE!"

As a Gunner, one of your biggest advantages is the i-frames you get from Stylish Rolls, so you really have learn Gemini's tells and use those i-frames to avoid taking damage, and balance that out with your attacks.

High-level solo content in this game is very much geared toward learning tells and dodging/Perfect Guarding rather than just attacking and trying to face-tank stuff.

900 hp? You're probably getting 2 shot like that by PD. I would suggest getting a guts drink and once you are more comfortable to transition it into an attack drink. While @AndrlCh is right in that avoidance is best, you can't learn the fight on the floor. Don't forget to eat a jerky and get a boost from alliance tree.

If you are unsure of your ability to solo gemini, try practicing a no-hit run on the story version. It's only differences are the lack of the line lazer attack, slower go-carts, and no 4th phase. The only differences you will see are damage scaling related. And if you think that it dies too quickly, take a weaker weapon. Your equipment is more than enough so now all you need to focus on is the fight itself.

thank you @ViolaCrossfire and @AndrlCh for the response and feedback. though i'm still open if there are any other advises .