I agree with your dad but one thing I'm not fully understanding is the enemies killing you instantly. And this is coming from today where I slogged myself through Neomuna's public events to get the weapon patterns for ... more time than I'd have wanted to spend (6 hours). Which is a constant state of Legendary difficulty + I play with high framerate on PC which is prone to enemies dealing more damage than usual and I never got 1-shot. Sure, I'd die decently fast if I got caught out in the open with my pants down, but that's multiple enemies shooting at the same time. I looked at your characters and you have them all set to PvP loadouts with low resilience, and that is going to hurt you a lot in PvE. You have 30, which is 5% reduction. Aim for 50 (14%) or 70 (20%) reduction and don't forget the additional damage dampeners like Concussive and Arc + Solar reductions for Taken enemies. Leg mods for Orbs to give you more health + start health regen on pickup are also life savers. Edit: probably not even useful information, you've been in this game longer than me if you started in D1. I'd assume you knew this already and I apologize for the ramble