I am on the fifth mission, which is the infiltrate a Borg vessel that retake some Isodesium they stole from me in the last mission. I have been given an 'Infinity Modulator' designed by Seven-of-Nine which uses the same weapon energy as the other Federation weapons (compression rifle, grenade launcher) but unfortunately I have run out of weapon energy and only have weapon crystals left.
The Borg have steadily adapted to all of my other guns one by one, and now are completely invincible to all of my attacks;
My AI squad mates all seem to have ammo but they only do a fraction of the damage that I do, so it takes them 4-5 shots per drone to take it down.
What is the best way to deal with the Borg when you have no weapon energy left for the infinity modulator weapon?