Help not dying

Im at 550 now so everything is ultimate difficulty. This is way harder content than I typically play in Destiny. Before the rework I left GM nightfall and Raids alone. They're just too hard for me. Now that the whole game is harder than a GM with the ultimate difficulty how do you do this? Im getting swarmed by enemies that never miss or reload. Every hit I take almost kills me and I die before I can even make a dent in the adds. This taken version of salt mines is the worst so far. These little drones have kicked the difficulty up to a place where I feel like my Titan is just really weak and cant hang. Don't really care about the helmet just bummed I cant beat a solo op at 550.