Textures don't usually reduce FPS, they'll eat up more VRAM so you may have a micro stutter when loading a cell because you VRAM is full and the game takes longer to load but that's it. It would be useful if you could tell us which GPU / CPU / RAM you're running, lowering the graphics won't help a lot if it's your CPU struggling. Fallout seems to have troubles with 60 FPS, it'll struggle to reach it on my GTX 760 when I drop the quality A LOT, but it'll still be able to reach an easy 30 FPS when I max out almost everything, I ended up locking it to 30 FPS. You might want to try using MSI Afterburner to check on your GPU / CPU usage, if one of them is running 100%, then that's what's bottlenecking you. The Cambridge police station is also on of the WORST place in the game in terms of performance. I don't know why but when near it, my framerate will drop to the mid 20's, even with all graphics settings lowered and with a GPU and CPU usage below 40%, it makes no sense. I know you've said you tried lowering the graphics, but did you reduce the godrays quality and shadow distance to the minimum ? These two options are absolute monsters in terms of performance and they'll destroy your framerate, especially shadow distance when near the Cambridge poilice station. You won't be able to have a 50-60 FPS in sanctuary AND at the police station, this place is so bad that if your average framerate at sanctuary is not a locked 60 FPS with a GPU usage under 75%, you will experience drop in framerate. So as I said you may want to try lowering the godrays to low (They'll be pixelated but if it works there are fixes for that), or even try to disable them alltogether by opening the console (~) and typing in "gr off". There's not much more I can help you with without knowing your specs.