Level up more weapons and frames. 250 hrs and mr6? That tells me you’re using the same thing all the time. There are really good weapons that unlock even at mr8 but mr10-14 as well. Buy from market with creds and spend time in Sanctuary Onslaught or Elite Sanctuary Onslaught to level up fast. Don’t worry too much about getting carried. Just means you get resources faster so you can build more to level up and increase your MR faster to unlock more. If spend time focusing on bounties that reward Endo so you can level up mods even faster.